Is it possible to upgrade the CPU on a mac mini? I want to upgrade the CPU on my Mac Mini (Late 2012). I currently have the i5 2,5GHz version but want to upgrade to a better CPU. Will it be possible to upgrade to the i7 2,6GHz that is on some of the other late 2012 mac minis?

I know it is recommended to upgrade the motherboard instead, since the soldering is very difficult to do, but will I have compatibility issues if i manage to replace the CPU successfully?
"The soldering is very difficult" is rather an understatement.

The CPU architecture is BGA [Ball Grid Array] which requires a special machine to replace.

If all you have is a soldering iron, you can forget it.
eBay has BGA rework stations from about $£€ 400 to 4,000.

Once you've got the gear, then you could watch this YouTube video to see how easy it is… https://www.youtube.com/watch?v=GK62KML0D04