Disconnecting pool pump housing from piping
The housing , after viewing the photo is attached to the discharge 1 1/2 inch plastic pipe. Although there are threads in view, you can also see a ring of glue (?) just above the pipe threads. So if there is no nut that would tighten to the pipe threads most likely you will need to cut the pipe to remove it from the housing. If the hole in the housing isn't very large you could try plugging it ,too.