Shanling tube cabe removal assistance

I can not get the lower tube cage ring off my Shanling T200A CDP.
Can anyone assist?
What's the trick here. I see thread in the posts but they do not turn...Trying to do some tube swapping and the WE 396/ Raytheons are very hard to remove and are much smaller. :scratch:
was it the Shanling that tubes cant be swapped by the customer?...I think there is a player that the tubes wont come out to swap, I could be wrong but it just might be the Shanling. Dont quote me tho:)
I was never able to completely remove the lower ring -- I could get one post out and then had to rotate the ring away. The first time I changed tubes I had to use a needle nose grip to loosen the post on top of the lower ring -- wrapping the post in something to protect it from scoring with the needle noise. Hope this helps.