If you don’t want to spend money:
To WL, just take the monorail or boat over to MK and then the boat or bus over to WL.
To Trail’s End, boat or monorail to MK and boat to FW.
Are you going to wilderness lodge and then to Fort wilderness for trails end?
From the poly, the best option for either would be to go to MK and take the boat or bus. Wilderness lodge and Fort wilderness have separate boats to each. They both also have a bus option from MK.
If you are at either the fort or the lodge and want to go to the other, there is a direct bus between the two.