There are a couple of possibilities, none of them especially easy.
First, it looks like there might be a union nut right against the pump body. If that unscrews the pipe will come off. However, if you do that you will probably need to fine a new pipe portion of the union fitting as the old one will be difficult to recover.
Another approach is to cut off the valve body, leaving the glued joint between the valve and the pump intact. Once you have done that there will almost always be a pipe size that can be glued inside the resulting stub. That will then require a fitting to increase back to the normal pipe size, and will take up a little bit more room. There will be a tiny amount of flow restriction from this approach, but that is not significant.
The final approach is iffy. It also starts with cutting off the valve body, leaving the glued joint between the valve and the pump intact. Then, working carefully, make some cuts in the remaining portions of the valve stub so it will come out in sections, then heat with a hair dryer, and work on scraping out the old valve stub with a chisel. Sometimes, not always, you can remove the remaining parts of the valve still stuck in that short piece of pipe. However, it doesn't always work, a properly glued PVC joint will never come apart, and once started there is no real way to turn back.
