I put this cabinet together last night by myself.  I made a few mistakes but caught them quickly enough so that is wasn't that much of a problem.  when it says "attache pins" it means screw them in the piece you will connect with the piece that has the cam locks.   

I have put together lots of this kind of thing, both lesser quality and similar quality and never before have I recieved a package of extra parts!  I needed it twice and was very grateful for it.  

Love the cabinet! It is very good quality - hard to believe for the price. No cardboard back!   Holds tons of stuff.