Changing image on header and sidebar

Link might help..

Sure !

https://www.aircraftprofiles.dk

#header {height:250px;background:url(‘https://aircraftprofiles.dk/wp-content/uploads/header.jpg’) no-repeat;}

#footer {clear:both;width:100%; text-align: center; height:250px;background:url(‘https://aircraftprofiles.dk/wp-content/uploads/footer.jpg’) no-repeat;}
These images are in uploads folder.. I think sandbox theme provide option for custom header and footer imaages..

how do i replace the existing images with new ones ?

As suggested, take a look in your themes options, you may be able to alter them there.

Otherwise just upload and overwrite new versions of the image you want to replace (links to some of the images given above).

To overwrite the files might be a solution, even i can figure out. Has anybody got a suggestion to what program i can use to view the files on my website (i′m on a mac).

No one ?

I use FileZilla, I believe you it is Mac compatible.

https://filezilla-project.org/

Thanks ! Now i′m just trying to figure filezilla out…But i′m pretty close (i think !), me website files show up, but i just can′t upload new ones (the new images doesn′t show up on my website)…hmm, guess i have to work on this one

Thanks for the help