Penetrator Panel Removal Hack?

[Boko (Bo Koppel)]

Hi!
Beware of the pressure, I sent a tube into the wall crushing the dome when it loosend…
Better tip in this post:

How do i open the bottom battery tube?

Bought an ROV a couple years ago and just starting to get it going now. I’m assuming they share common parts across manufacturers. The Vendor will not respond to emails and Blue Robotics wont either (even though i told them I am interested in buying a gripper arm off them-guess I’ll keep my money). I am trying to open the battery tube and it doesnt budget. I have removed the bottom air vent screw but the cap doesnt come off. Tried pulling it and turning it and it doesnt budge. How do I get it of…