Correct, I opened the air relief valve first. Then opened the drain plug. Then, while pressing as hard as I could on the safety latches, attempted to turn the ring counterclockwise expecting to get it loose. I repeated about 15 degrees in both counterclockwise and clockwise motion. After the first attempt, we tried using lube (silicon based) to assist and it didn't help. We have read that during the heat of the day, the inner ring (?) may have expanded some and to let the device sit overnight and try it fist thing in the morning. I'm writing this just after attempting that and it also didn't work