Take the bus to MK from POP. Then you can do several things. You could walk over to CR and hop on the monorail line there, and then ride it all the way around to MK, and then take the WL/Ft.W boat. Or you could just get off the bus and head to the MK monorail station and ride it from there, just makes a complete loop. Get on the resort monorail if you want to stop at the resorts, or the express which will take you to the TTC. Not sure if you can stay on at this point though. You may have to get off and re-enter before going back to MK.
When you are ready to take the boat to WL/Ft. W, head to the boat dock. Not the big steamboat type ferry dock. There is a dock that services the GF/Polynesian, the CR and WL/Ft.W. Get on the WL/FtW boat...it may stop at the CR also. Be sure to get off at Ft.W, not WL!! Saw someone do that before.