I get mine off but I do not know why they made the tube go all that way on that long base. They created a new base. They should have moved the shoulder half way up and kept the old air tubes. They would be easier to get off and they would have maintained the original capacity.
in order to fully control the wiring they extended the base, when they did a test on the old ones when they realized there was a issue, there was a 6% failure rate of doa phoenix xl and ones that died prematurely, when switching to this new base which lets them do the insides properly and then retested heavily, it was 1% failure rate.