What are you asking exactly?
I would learn how the rifle comes down and how it goes together before anything else.
I would then start with a hop up chamber, PDI
Then go with the cylinder, piston, spring guide, piston head, then spring.
Then look at a new trigger, depending on what spring you use
Then possibly a barrel, of course if you get a bad one from the factory that should be number 1 or 2.
Any other questions take a look at fuzzy's MK96 guide, he has alot of good info and pics in there. If there is anything else that you need just ask.