the gas block bushing is easy to install.dissemble the gas block but be careful not to lose the small bushing. change out tho old and replace with one that comes the kit. when putting back together make sure to evenly space the gap on the block and tighten in a x pattern. the buff. tech buffer and wolff xtra power spring do alot for the gun but don't be worried when you can't get the charging handle to lock back before you shoot the gun with the buffer because it needs to be beaten or broken in with a couple of mags.