That company will maybe take the old engine off you hands as a core if it can be repaired with new parts and re-conditioned. They will send you a new one, take off the old one, the things you'll need like carbs and flywheel and stator assy. ect., and send back in the crate the old core.
Keep us posted and let us know how it's going. If you need a manual you could join as a premium member and download a authentic seadoo manual from the seadoo forum library. Click on the "seadoo Manuals" link at the top of the page.
Karl