you could take the bus to magic kingdom and then the boat or bus to FWCampground... or you could do what we did and take a taxi/limo (the valet hailed us a car at the dolphin to HDDR and it cost $25 including tip... it was worth it!)
We took the boat from MK to HDDR. The boat drops you very close to the Hall. About a 4 minute walk. Then, I understand they have buses right there to take you back to the resorts. Since we did an earlier show, we just took the boat to CR, then walked over to MK (we love this walk) and took a bus back to our resort.