Hey guys...is it difficult to change a grip on your standard AR...say I have a Spike M4 Carbine and want
a Ergo Sure grip or a Hogue grip or a Mag-Pul MOE grip for different furniture...any other grips
you might think are better for the buck or better overall please let me know but the major question
again is how hard is it to change the grip any instructions???? thanks in advance

Probably one of the easiest upgrades to do. All you need to do is unscrew to bolt. The only thing you have to worry about is the selector detent and spring incorporated in the grip..

ETA: What I meant by the spring/detent is to make sure you don't lose it and you have to reinstall it in your new grip.

+1.  Just hold the rifle upside-down when you unscrew the bolt/screw and the spring an detent won't fall out.

Changing the grip is one of the simpler task with regard to an AR type rig.

With the bottom of the AR's grip facing you:

- Remove the plug/base, if so equipped
- Remove the hex/phillips/slotted head fastener
 * When the fastener has been removed, use care and slowly remove the actual grip. You will see the safety selector spring. The safety detent pin is  inside ahead of the spring. Do not lose these 2 items.
- With the safety selector spring and detent pin in their proper place, mount the new grip and tighten with the new grip's supplied fastener.

That is all there is to it.