You should be able to get a van cab...that would take most of you, maybe all of you, in the one cab. It's a very short ride from Pop to YC/BC.
If you choose to take the bus? Get on a bus to DHS by 6:45...they do tend to run a bit less frequently in the early hours, so if you just miss a bus, you may find yourself waiting for 25 mins for the next one. When you get to DHS, if it's an EMH morning, the boat will be running, so you can take that. If it isn't an EMH morning, you will have to walk. The walkway is easy to find...walk towards the canal when you get off the bus. Keep the parking lot on your right, the canal on your left. Walk about a minute or so, and you'll come to a downward slope to the left, heading closer to the canal. There should be signage saying 'walkway to Boardwalk'. take the sidewalk and just walk...takes about 20 mins. When you get to the end (all the way past the back side of BW), go to the left and up the incline. At the bridge, take a right and walk down to YC/BC.
I would take a cab though...that way you can leave Pop around 7:30!!