Same thing happened to me this weekend. My baitwell pump is right next to my livewell pump, I just switched them so I could keep water running on my fish in the livewell.
I didn’t see it mentioned above but mine have a little pressure locking tab you need to pull away from the housing before the motor will twist out. I would guess they all do so check for that before just trying to twist the motor out so you don’t break anything.
If they haven’t been out in a while or ever they may be pretty tight(mine were) so be gentle you don’t want to crack or break the housing off where its mounted.
The new motor I bought didn’t come with any plug or connectors so you’ll need to get the old one out and wire up the new one as well.