How do I remove the passive radiator on a Miatone BOOM BOX / Q12?

These speakers are great. I love using them in my garage, but they don't last long enough when the volume is up and TWS (True Wireless Streaming) is active.

They both say they have 2500mah batteries and that just doesn't last long enough using both together.

Today I tried to tear down one of them to see what I would be up against.

1. I removed the grill by opening the charging port cover and prying from the edges of the grill.
2. The rubber ends of the passive radiators were removed by pulling up on the edges and lifting them off.
3. I unscrewed the eight Phillips heads screws that hold the main body of the unit together. Then I unscrewed the 12 smaller Phillips head screws that were on either end of the unit, surrounding the passive radiators, and removing the plastic ring.

At this point I got stuck. There seems to be adhesive around most of the unit for water resistance and to keep the vibration of the unit to a minimum. (It feels pretty solid)

The adhesive seems to also be holding down the passive radiator when I tried to split the unit in two halves. I don't want to rip or tear the rubber of the radiator by prying it in half.

Any help or advice would be greatly appreciated. Thank you.