I replaced some parts on my M1 MacBook Air.

For 90% of the parts it’s honestly pretty easy to work with. You just need a few screwdrivers. And I sourced all my parts from eBay.

The documentation is excellent:

https://support.apple.com/en-us/100586

The only thing that’s egregious is the batteries. They tape the batteries to the case, and to remove them you have to do this complex twirling motion with tweezers to pull the tape out from under the battery. If the tape snaps during this then the documentation basically says get a new case.