[AnthonyG]

Don't just take it apart for the sake of taking it apart.

I'm the only one who has worked on my guns but most of the changes have been simple stuff like changing out a spring, cleaning and re-lubricating a used gun I bought...

The first time I opened my m4 I broke my selector plate, and that was after I had watched a half dozen or more videos on the breakdown process.

I say all this because working on my own guns hasn't been without problems. Ive learned that not all parts are created the same. Fractions of a multimeter difference between one part and the next make a difference, the shore value of rubber between one bucking and the next can cause your gun to stop feeding. If you really are insistent on doing work yourself I've learned when starting out replace one part at a time, then test it. If it works replace another part and then test it again. If you replace several parts at once it will be difficult to diagnose problems should they arise.

Just my 2 cents.