Sometimes when replacing the cabinet it bows out a little, and flexes back and forth.....so you have to kinda help it out when sliding it all together to make sure its all lined up before you put the clips back in place.....
on the frame near the back, on each side should be little extrusions sticking up, that slide into the slots on the body......when lined up right, the the body and frame should fit perfect together.....
a little tricky....the body should be tilted as your sliding it towards the machine, once the front makes contact with the frame, start lowering the cabinet towards the back....and everything should pop into place for the most part, sometimes you have to push the back into place.....and then fasten the clips....
good luck