We stay at WL often. Your best bet is to catch the bus to MK then the boat to WL. The boat ramp will be directly in front of MK entrance. It takes no more than 10 mins to get there by boat. Do this in reverse to go back to POP, but make sure MK will still be open as transportation will stop 1 hr after park closes.
You will be directed by WDW transportation to take bus to DTD then transfer to WL bus from there. This route can take a very long time.
Allow at least an hour for travel time and you should have no problems. If you get to WL early, check out the scenery. It is a beautiful resort. Have fun at WCC. Its a hoot!