I've not had to replace the line yet...
but here is a link to a page from the H240 manual. The drawing is very similar to the one in my H19 manual. To help in the replacement it looks like it would be a good idea to lower the mast and remove the mast step from the deck. This will open up the top of the uphaul 'tube'. The line feeds into a thru hull which is attached to a PVC tube running down the front of the mast compression post. The lower end of the tube attaches to another thru hull. There are sheaves at both the top and bottom. Hopefully someone will chime in with practical experience in this task. Good luck.
