I purchased a bushmaster not too long ago with Hogue grips installed.  I do not like them so I bought new ones, But  since the hogue barrel grip is aluminum and dosent snap together like the original plastic ones how do I remove it?   also it looks like i am missing some parts in front and behind the new plastic grips,  am I?

I'm assuming that you are talking about replacing a Hogue free-float tube with standard plastic handguards. I'm not familiar with the Hogue, but from you description, it sounds like a one-piece tube. If it is, you'll need an action block and a vise at the minimum. First you'll have to remove the flash suppressor. Does it have a full front sight base or a gas block? If it has a standard full FSB, you have to remove it first by driving ot the taper pins from left to right with a 3/32" nail set and hammer. If it's a gas block, there should be set screws that need to be loosened before sliding it off. You'll need to take a 1/16" punch and drive out the gas tube roll pin in the front sight base, and remove the gas tube. Then you have to unscrew the FF tube with a strap wrench, or perhaps an armorer's wrench if the are holes in the rear of it.

To install regular plastic handguards, you need a new barrel nut, delta ring, snap ring, weld spring, and front handguard cap.