How do I remove & replace tranny accumulator cover?

I replaced both gaskets on tranny pans and now I am getting a leak from the accumulator cover. My mechanic verified that this is where it is coming from. He removed the snap-ring but could not get the accumulator cover off. He didn't know how to remove it and didn't want to mess up anything, and suggested a tranny shop. I found someone on this site that gave the part number and said they had the same problem, but I haven't found anything on whether to unscrew, pry off or how to remove the accumulator. Has anyone replaced this and how do you get it off? Also, my mechanic said that the GM version of this has a o-ring that needs replacing? Thanks for any help or experience advice anyone may have.

I pop them out with a pry bar

Hey I just had mine done by the dealer as it's covered under warranty.