Decrypting Header.php

How do I decrypt this script?

<?php // This file is protected by copyright law and provided under license. Reverse engineering of this file is strictly prohibited.
$OOO0O0O00=__FILE__;$O00O00O00=__LINE__;$OO00O0000=5148;eval((base64_decode(‘JE8wMDBPME8wMD1mb3BlbigkT09PME8wTzAwLCdyYicpO3doaWxlKC0tJE8wME8wME8wMClmZ2V0cygkTzAwME8wTzAwLDEwMjQpO2ZnZXRzKCRPMDAwTzBPMDAsNDA5Nik7JE9PMDBPMDBPMD0oYmFzZTY0X2RlY29kZShzdHJ0cihmcmVhZCgkTzAwME8wTzAwLDM3MiksJ0VudGVyeW91d2toUkhZS05XT1VUQWFCYkNjRGRGZkdnSWlKakxsTW1QcFFxU3NWdlh4WnowMTIzNDU2Nzg5Ky89JywnQUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVphYmNkZWZnaGlqa2xtbm9wcXJzdHV2d3h5ejAxMjM0NTY3ODkrLycpKSk7ZXZhbCgkT08wME8wME8wKTs=’)));return;?>
kr9NHenNHenNHe1lFMamb3klFoxiC2APk19gOLlHOa9gkZXJkZwVkr9NTznNHr8XHt4JkZwShokiF2A2Yy9LcBYvcoAPF3OZfuwPcmklCBWPkr8XHenNHr8XHtXLT08XHr8XHeEXhUXmOB50cbk5d3a3D2iUUylRTlfNaaOnCAkJW2YrcrcMO2fkDApQToxYdanXAbyTF1c2BuiDGjExHjH0YTC3KeLqRz0mRtfnWLYrOAcuUrlhU0xYTL9WAakTayaBa1icBMyJC2OlcMfPDBpqdo1Vd3nxFmY0fbc3Gul6HerZHzW1YjF4KUSvkZLphUL7cMYSd3YlhtONHeEXTznNHeEpK2a2CBXPkr9NHenNHenNHtL7eWPvhI0hwtnWDo90dZnKcbi1FZnADoascW0hhJ8YtjslC2ivwtF8wAONW1OcArAIDuOsdtnWaAkHUAHIwJ0vR1FzWZ8vOyOrwyiwar1HwerVHtnAFMyVF2l0DB9VCBXvR0aKwJEJDuO0FePvR3f3fZ53HZ5vFMFvaywvGoi0dBXxR0OAOt94DuOsdersfukidmYpfolvdMySRMO0ctw+eWP8DuOsdtn4dBxVFz0JDuO0FePvR3f3fZ53HZ5vFMFvHTL5KU94DuOsdtwIkzSIdoyVc3aic2agCbO0FMlJfbOlFZIpKZE7cBYPdZEmNI0heWPkNoilCBWIFukvcMlScT0JDuO0FePvR2fsFoFVd3kmR3iMdJ8xHUw+eWPkNo1lforIDuO0Ft1lFbapfj0JW29VfoaVft1AGbnlwJnjd250cB50NUwmKZnJdo9mDB5MdZImDuOsdy90GbnlkZL7weslC2ivwtF7woYPCbkzcbW9kzSICMxvc2lVcM8Pk2YPCbkzcbWmhTSIK2ajDo8IkZwIRz4YtI0htTx0DbOScT4mKZn3Fy90DbOScUImkMxiFbavKZFSwuOZfBASwtfZDBfPftFpKZE7cBYPdZEmwtF7wokSd2fpdMcvhtfVCB1lkZL7weslC2ivwtF8R3OpfoxlNI0heWPYtJF7wt8vwrflftn0DoAIfbYlFJnjDo9pC2azwocvFJn0DoAIfoildBAVeWpmdo9JCBXIko9XfolvdmH7eWpMd3klCBYPwtILd3n0DB9VFZniFZELfMySfBApwuSYtIlpcJEPc2a0b3YlfuOpdMfzhtELfMySfBadk2lLk10IhUE9NT0IOLyHA0ApwuSIktO2CBx1caSmDBWmbUE9wtO2CBx1caSmF3OLk107wu0IcBxzcUn7wtWLfMySfBadk2lLk10INUnmcbOgF2a0folVc3HPwtO2CBx1caSmDBWmbUEpKZn9eWp9eWP7cBYPdZEmeWPYtILkkzSIDBCIhtOXDo9VGy90DoascT09wLkZDBfPftn0DoascUwpwuSLF3O5doaMDBxlNUkJFMlmDuOgF3O5doAVC3Yzwjs9weslC2ivwtFktUF7wolMwtILFoivdmigfoildBA9NUkrCbkqwuOPcB1lwJLIGZOzfulScBcpdoA9wMOiFMsgF3O5doAVC3Yzwjs9weslC2ivwtFktUF7wolMwtIiDbYTcbWPkunPd254b3OPcB1lhULIGZOzfulScBcpdoA9wMkZDBfPfy9zfulScU5jF3HJK30IK2ajDo8IkX0htWL8dolVDZnZcBX9wmY0GBxlF2ilcbWJwoiZcBC9wJF7wokSd2fpdMcvhtfzfulScbYPcBa0b2OpFMajfo9ZGUFpKZE7cBYPdZEmR2YzFZ8mKZnlC2ivwtOzfulScBcpdoA7weslC2ivwtFJwuO5FoA9wmOlGuWvC3YzwJnscBOpCT0JF2YZcBaVwJEvNI0heWPktUF7wolMwtILFoivdmigdBaVfT09wLYvdoxiFuYlctwpwuSIK2ajDo8IkXLktTxSDB5qwuklde0JF3O5doazDoalftwIDuklcj0JkzSICMxvc2lVcM8Pk3Y0GBxlF2ilcbOgcolZcBY0d3k5kZL7weslC2ivwtFvC3YzR21ldmAsd3n0RMYzFZwIfulXcT0Jfoa4ft9jF3HJwo1lcoliNUkzC3klcB4Jwt8+eWPktUF7wu0IK2ajDo8IkX0htTXiRU0IUlyaOakcwrxpCmkiFmLIRU0+eWPkNuYjFMlXftn0GbnlNUk0cbi0R2pifMyzC3kpFuWJwuYZCz0JkzSICMxvc2lVcM8Pk3Y0GBxlF2ilcbOgcolZcBY0d3k5kZL7weslC2ivwtFvDmHvDmy1cbk5RMpzwj48R3YjFMlXfe4YtIL8wU0swrcnOrAIDB4IOLyrOUnvfbWIF2xpcoAIRU0+eWPkNuYjFMlXftn0GbnlNUk0cbi0R2pifMyzC3kpFuWJwuYZCz0JkzSICMxvc2lVcM8Pk3Y0GBxlF2ilcbOgcolZcBY0d3k5kZL7weslC2ivwtFvDmHvDmy1cbk5RMlVdMaZcMyLcU5QFZw+Nt9zC3kpFuW+eWPYtIL8F2YZDbn0wuO5FoA9wmOlGuWvDMy2CbYjFMlXftwIF3kjNUwmKZnJdo9mDB5MdZImF3O5doazDoalfy9LDbklC3OvFmLmhTSIK2ajDo8IkZ9QFZ9XDBsiC2ivd3YlRMpzwj48R3YjFMlXfe4YtI0htTxSDB5qwuklde0JCBx0cbkVCbOlwJn0GbnlNUkiFunSDBYifolvdJ9ZF3HqGo1SwJn0DbOScT0JAlYTwewVHtwIDuklcj0JkzSICMxvc2lVcM8Pk3kzFzkgfbkSkZL7weslC2ivwtFJwt8+eWPkNoxpdMSIFMaSNUkiduOlFM5ifoAJwuO5FoA9wmOlGuWvGo1SwJn0DbOScT0JAlYTwt45HJwIDuklcj0JkzSICMxvc2lVcM8Pk3kzF191FMXmhTSIK2ajDo8IkZwIRz4YtIL8dolVDZnZcBX9wMySfoaZdMy0cUwIfulXcT0JCbnXdoljCbOpd24vCbOvdUs4dBXJwuOpfoxlNUknfo9swerVHtwIDuklcj0JkzSICMxvc2lVcM8Pk2y0d21gfbkSkZL7weslC2ivwtFJwt8+eWPYtIL8dolVDZnZcBX9wmnpdMfJCBYqwJnPFMaMNUwmKZnJdo9mDB5MdZImFolVc2kiC2sgfbkSkZL7weslC2ivwtFJwt8+eWPkkzSIf3ngc2a0b2yZC2ipfMazhtf0GbnlNB1vdmOPduLMcM9ZdBy0NBxpdMSmhTSIK2ajDo8IkXLmKZEvR2YvdB1ldmOzb3nvFuaXb3YjFMlXftIpKZEvRZnvcMCICmLIcoaMCbaSftEhK2ajDo8IkXLmKZn3Fy9PcByLhtL7weslC2ivwtFkeWP8F3O5doAIfulXcT0Jfoa4ft9jF3HJNI0hw3OPcBkvcul7wunicoOpdMFsfo9XKJF7woajDo8IkunPd254b3OvFuYXCBYlKZE7cBYPdZEmFuI7gW0hNt9zfulScT4YtI0heWPYtjXvDoaice4YtI0hNokvcuL+eWPYtjxLDbCIDBW9wmOPcBkvcuLJNJEYtjxLDbCIDBW9wmOPcbnic2AJNI0heWPkNoOpfJnpce0JdMy2f3kiFtw+tW0htWL8CUnPFMaMNUwmKZnlC2ivwoflfy9vFuOpd24Pk2ivdBAmhTSIK2ajDo8IkZ8JNjxpdBFIF3kjNUwmKZnJdo9mDB5MdZImF3O5doazDoalfy9LDbklC3OvFmLmhTSIK2ajDo8IkZ9pdBymcbHvdo9mdZ5mDBCJwoySfe0Jdo9mdZwIRz48R2r+eWPktTx1de4YtILktTXiRU0IwtEITr9uTZnMd2xSd3flctnJGW0htWLktaOvFtnYCBlVwr5ifMlmCbOpd24ICMyZeWPktWLkOBOpftnJcBxvfZnidMWIcB50cbwIfoilwoi5FoaZdolVDZnMd3wIfoilwunic2AYtILktWlod3wIAoymcUEkwj9XCBflb2lLNTxWCBflb0lrNJwYtILktWlod3wIW2y0cB9mFmLkwj9jCbW9NrYify9kOe4JeWPktWLsRT4YtI0htWLYtILktTxSDUnjdoyzFz0JC29sFoyVGUw+eWPktWLkNorIDuklcj0JDB5LcbIVFoiXwj5wd21lNt9iNI0htWLktTxiwoiZcBC9wj9XCBflb2lLNUF7woajDo8IkunPd254b2yJd3a0b2lLKZE7cBYPdZEmwj5nCM91feXvCT4YtILktWL8CUnPFMaMNUw/Foymca9pce0mKZnlC2ivwtOXDo9VGy9jd250CBY0b2lLKZE7cBYPdZEmwj5ed250CBY0Nt9iNI0htWLkNt9SDT4YtI0hNuaSwolLNUkscB51wj4YtILktUF7eWPYtILktbfXb2xpF3OgC2y0cBfvFMllFZImF29Zfy9jd2x1dB49dMyscUcvFuOpd25jd3aVfe0XkMa4C2x1coA9kZ4LFoivdmigcbijduaLca9jCbWVkZc0DbOSca9SDT08doLIC2xiF3H9wMYift10DbOScUw+W2y0cBfvFMllFzXvdoL+kZL7wt8vwoa4C2x1coAIC2y0cBfvFMllFZnJGUnldmOlFMlVcZnjCbOlc29ZGUn2CBx1cU4IcBFVwoa4C2x1coA9HUXZReCSHTrYtI0htWLkK2ajDo8IkzXvfBX+eWPYtILktTXiRU0Iaoilwrcvd3OlFJnpFZnpdJn0DoAIDoaicoaZwo5vfZE6hUEsRT4YtI0htWLkNoxpwoYSCbYzNUkMd290cbwsfo9Xwj48R2xpNI0htWLkNoxpwoYSCbYzNUkMd290cbwJNJcjd3n5KZEmKZnlC2ivwoOifoAPwlLJhTSIK2ajDo8IkZEMdBlLco90KZEmKZnJdo9mDB5MdZImdMyscUFpKZE7cBYPdZEmRjXvdoL+eWPktWL8doLIC2xiF3H9wMcvd3OlFJw+WBxSwykpc2i0FZnUcbYlFmclct48R2xpNI0htWLkNoxpwoYSCbYzNUkMd290cbwJNJF7wokSd2fpdMcvhtfVCB1lkZL7weslC2ivwtFIFo93cbklctnJGUE8CUnPFMaMNUkPfuOXKJ8vf3f3RMcZcBAsFukldBl1dU13d3kLFuklF3HsfoildBazRMYvdUwIFMaSNUkLd2cvdoxvfZw+OmklcUnWFMasDbaswyfvFMOXFMazFZnADoascbH8R2r+Nt9SDT4YtILktTxSDUnjdoyzFz0JcM9vfoaZRBaVctw+NorIDuklcj0JDuO0FePvR3cidolLCbOvFJ53HZ5vFMFvC2ilC2S/fbkpNbklcMaZcbwJNmiPfo1SNt9iNJn2CBxpctnidMWINorIDuklcj0JDuO0FePvR2ppc3YifZ53HZ5vFMFvC3YzRbcidolLCbOvFJ9jDoajDZ9ZcBclFMaZwj5jF3H8R2r+wucidolLNt9SDT4YtI0htWL8R3aSNI0htTXvcol2NI0heWP8wU0swoaVctnPcByLcbwIRU0+eWPmKX==