How to remove round ceiling A/C vent

[BobinICT]

I've tried to unsnap the rotating part of the vent to get to what I assume are screws attaching the assembly but I just can't seem to get it unsnapped without causing damage. I've tried automotive trim removal tools, just can't get a decent grip in there, one, then two small flat tip screwdrivers. There appears the be a tab of some sorts in one section of the vent that when prided on each side with the flat tips, get some disconnection but not enough to get the vent to pop out.

I want to check ducting in the ceiling for proper sealage and overall attachment because I seem to have one vent not producing similar airflow like the others.

[Second Chance]

I used the search function (top right) and found this:

https://www.mygrandrv.com/forum/show...922#post330922

Rob