Yes I have done the replacement twice but on a 1996 190 Popular.
Depending on the model and year of yours, it may be different.
#1 drain the tanks before you start!!!!
#2 You want to get in up on a hoist (if possible) but at least with the front wheels up on a ramp to give you clearance to work underneath. Block the rear wheels so it can't roll off.
#3 make sure your drain valves are CLOSED
#4 Remove the end cap and the end cap connector from the flexible hose by removing the hose clamp. Take the connector off.
#5 Remove the screws from the rear of the outer PVC tube which houses the flexible hose.
#6 Slide the PVC pipe off of its mount, exposing the end of the flexible hose and the hose clamp. Remove the clamp and pull or cut the hose off the mount. DO NOT HAVE YOUR FACE UNDER THE END OF THE HOSE.
#7 Remove the hose by sliding it through the PVC outer pipe. Slide your new hose ( new hose should be best and thickest quality you can find, and at least 10' or 15' if it will fit in PVC pipe length)
#8 Slide new hose through PVC pipe and connect with hose clamp to drain.
#9 Slide PVC pipe over mounted hose and secure screws.
#10 Replace the end cap mount and secure with hose clamp. You will have to rotate hose clamp to line up with slot in PVC pipe.
NOTE: The hose clamp screw MUST slide INTO the slot in the PVC pipe when your hose is retracted or the hinge will not close so you can screw on the small drain cap that locks it from falling out on the road.
Good Luck ...........don't get wet!