It is tricky finding an appropriate spot to drop down onto the ledge below the bunker, but several people have reported doing so. I tried for a few minutes, and then just went to the teleporter (on the island across the water from the bunker).
The ledge on the island with the teleporter should be easily accessible to transform above. Approaching the bunker, the ledge you need to get to is directly above the left nest tower (or above where it was, if you have taken it out already); as a human you can easily walk off the ledge to land on the nest.
