So they finally cracked and I need to replace them with the aluminum ones. However, its my 1st nitro and I can count how many times I drove it still. Is this a difficult replacement? I know I won't learn till I do or try it, but for all the people that have done this before, should someone who is still very new to nitros and nitro wrenching, try to replace a diff himself, or wait to learn on something less difficult.