If your drive is stuck up (too high), you will be able to lower it by disconnecting the lines. As for fixing the problem, you can't do the job right unless you pull the boat out of the water. If you replace the pump and use new fluid with the same faulty trim cylinders, you are going to end up with another milkshake. Rebuilding/replacing the trim cylinders is a quick job, just costs some $. You could also be lucky and it could just be a leaking hose or connection, which is an even quicker fix. I'd pull the boat for a few hours and replace them if it were mine. here