You can translate almost all texts using po-edit;
copy the file lang/cookie_opt_in-nl_NL.po to lang/cookie_opt_in-pl_PL.po
(I think pl_PL is the correct language tag, you can maybe find that in your wp-config.php file if you installed the polish version)
then edit it with po-edit, translate all texts and save.
this will result in two files; cookie_opt_in-nl_NL.po and cookie_opt_in-nl_NL.mo
both are needed.
The buttons, however, are images.
There are PSD-files included in the css folder to allow you to create translated buttons
cls-accept.psd and cls-save.psd
save the polish versions as cls-accept-pl_PL.png and cls-save-pl_PL.png
then, edit the style-sheet of the used skin to add lines like this:
.lang-pl #cookie_opt_in_container button.coia-accept-all {
background: transparent url(cls-accept-pl_PL.png) no-repeat left top;
}
.lang-pl #cookie_opt_in_container button.coia-ok {
background: transparent url(cls-save-pl_PL.png) no-repeat left top;
}
when done, if you want, you can send the resulting po, mo and png’s to me and I’ll add them so thy will stay with updates.