David,
When I replaced the very same hose on my boat I fastened the new hose to end of the old hose (so the ends were flush with each other) at the toilet end with about 12" of a good duct tape. I then carefully pulled the whole thing thru.
Suggestions:
1. Heat the ends of the hose in very hot water and slip them on before they cool. Makes life MUCH EASIER!
2. While you're at it, remove the macerator pump & inspect underneath for leakage. They can leak at the seal between the motor & impeller and you won't see the leakage because it's hidden.....but you sure can smell it. Repair kits are available for about half the price of a new macerator.
