Transformation: fold the heel spurs under the toy and against the feet. Fold each leg out to the side at the ball jointed hip, then fold each hip inwards bringing the legs flush together mating the pegs and holes. Excessive force and some sort of lever will be required. Fold the wheel halves to the outside of the leg. Fold the combined leg section onto the robot's back. Bring the wheel halves together under what was the robot's waist. Pull the engine block up & forwards into a higher position on the robot's chest and lower the head about halfway into the block. Rotate the arms upwards, folding the wheels on them out to the sides. Fold the bar against the front of the hand. Bring each shoulder down and in locking the hands together in the space occupied by the robot's head and locking onto the top of the vehicle on the robot's back. Clip the guns onto the rear of the vehicle.
Backfire's vehicle mode is a form of motorised Trike, mainly olive green with two wheels at the front & just one at the rear. Unfortunately he has exactly the same problem as Icepick: the vehicle is about twice the size it needs to be for the figure, meant to be Spike, but since they're in an all enclosing body suit & helmet it could be any one. I suspect that Major Tungsten should be Spike as there is a resemblance there. Nice clear orange head light on the front of the vehicle!
Weapons mode: separate the rear wheel & fold out to the sides. Fold the top of the vehicle back and turn the vehicle over. Fold the front of the vehicle, to the handlebars, under the saddle and lock in place.
BIG GUN, possibly the largest hand held gun formed from a Transformer for use by another Transformer. Waaaaay out of scale for a deluxe toy to hold you're looking for something a little large and preferably with a closed fist hand as several of my open hand toys have had trouble holding it. Though I'm not sure I'd want to be holding a cannon called Backfire.....
Buy if you want the handgun, otherwise another pass I think.