Fill will hot PBW, and set upside down for a while, make sure to run some out so that the post is full of PBW. This is in case any beer has caused the post to stick with hardened sugar. Seemed to help me a couple times.
Then, deep well 1/2 inch 12 point, long handled 1/2 inch breaker, and a mallet. Righty tightly, lefty losey.
Good luck!