[tunabreath]

There's another grub screw under the vert grip.

Stick something narrow into the end of the vert grip and lift up the end cap. Unhook the spring with some pliers or something (don't stab yourself with the sharp, spring propelled hook end)
Knock the pin that holds the vert grip out of the barrel hub.

Look at the hub from below, you should see the grub screw right where the end of the vert grip sticks in to lock in it's vertical position.