This took maybe an hour for everything. I cut off his back kibble, but I did it one joint closer to the kibble than everyone else, because I wanted to leave that spacer piece in Prime's torso. I cut a very ugly slot into Prime's forearm for the gray plastic to slot into. Having a shield on the forearm looks better/makes more sense than having it in the fist like a lego figure. I did the leg mod, too. It's really subtle, I'm not sure why it's so popular, but it does make him slimmer and more dynamic, which is what I like. I also cut off his hip kibble, sanded it very thin and just keep it on his shoulder assembly. I'd toss it entirely because it gets in the way a little, but the vehicle just doesn't look right without a full bumper. Oh yeah, also shaved down the wrist part of the fist so the hand can rotate almost 360 now. I intend to paint the panel lines and accents with some black light reactive paint at some point, but money is really bad now. I'll probably fill in his forearm and put in magnets, too.
Really? Why wouldn't it attach properly? The tutorial is: Trim that gray joint where it connects to the back so that it can unclip from the pin that holds it in. Carve an ugly slot in the forearm. Shove that gray part you just cut free into the slot. Added pic with him holding his rifle with the variable axe in scythe form, too. He pulls it off pretty good.
