98 custom Universal Parts Kit

I bought one of these yesterday, and I have it in front of me right now.... the problem is, I am pretty new to paintball so some of m explanations might be very vague...  This was the smaller kit that sold for about $12.

1 Square bolt

2 Regular body screws

1 large O ring? 

2 of those silver colored cylinders that are used to hold the trigger

1 smaller silver piece... kinda of cylinderish, but it has 3 levels were it gets thinner.

1 velocity adjuster screw

1 metal clip... shapped like a "U"

1 longer screw

2 nuts

1 black cylinder piece

1 orange plastic piece... found in the area near where the hopper attaches

Mineral oil

1 regular size O ring

1 bolt spring

1 black plastic piece... cylinder, it looks like its for holding a spring?  No clue.

I hope that was helpful... sorry I am kind of a newb and I don't know what half of these things are.