I've seen a few customs of this figure and have been tempted for a while to remove the back kibble. Today I bit my lip, took out a sculpting knife and hacked at the connector......Ooooh.
Nah I actually carefully snipped away the parts of the swivel area. Then I did a quick modification of a roadbot axe, while the paints were out I did a quick redeco of some bland areas in black on pimes not-windows or windows? And his ab grill area then used a cocktail stick to trace the lines where I chose. Done

Now prime has an axe and shield and can go all medievil on ya.
The cab roof/sheild was not damaged in any way and slips back in for tuck mode, also used the two prongs to wedge it into his folded down fist and outer arm.