The pipes are plain old ABS that you can buy at Home Depot or Lowes. Just cut out the leak and replace with some new pipe and fittings.
You might need to cut off and remove all the downstream section. Then replace the leaky piece and use a standard coupler to glue the cutoff downstream section back in.
If the leak is where the round pipe converts to a square plate for the dump valve you might need to buy a new square piece to glue in from an RV shop.
To answer your question both ABS and PVC can technically be dissembled and reglued. But it's way way more hassle than just cutting the part out and gluing a new piece in.