going by your pic, i'd replace the pipe section completely on the top outlet there with a union on either end (, i mean the joints like your pic on the right with the gnurled screw on and off fittings..then you'll be able to undo the pipe as you need to without further cutting ever again. cut the pipe on the inlet and put a screw on and off fitting on the inlet as well..what i can't tell from the pic on the inlet end is how much pipe do you have to work with..if there isn't pipe further back at the bottom of the picture to play with then i would take off the top piece, then it looks to me like 2 people (one holding pipe,other lifting pump) could actually turn the pump off the joint and then add an adaptor and screw on fitting to your new pump, then size out and fit your top piece. ) i assume you have a pool store you can go to? if you tell them what you need or draw a diagram, they'll help you figure out exactly the parts you need. the place i get mine, if i keep the receipt, they'll take back everything i don't need in a pinch. hope you like the new pump!i love mine

it looks to me like whomever installed it never contemplated a need to replace the pump!