For a bug I need to check if a bug still occurs on upstream kernel 3.7rc7, and since the bug is related to fglrx I need to install a newer version as well that work with kernel 3.7. How do I do this step by step?
I got my answer by combining different posts on the ubuntuforums. This guide will use the 12.10 version of fglrx from the ati site. All these steps are done in a terminal. This guide assumes you have kernel 3.7rc7 installed by following the steps in https://wiki.ubuntu.com/KernelMainlineBuilds. It also assumes you're running Ubuntu 12.04, however the instructions for 12.10 are very similar.
Reboot it and it should work!