Moen Monticello hub problems

[Trevor Thomas]

HELP! I have a model T951cp 2 handle for my whirlpool tub. Typical problem with the plastic handle adapter broken. Cold side hub screws off just like its designed to and there's is a plastic piece with threads showing. Hot side screws off almost all the way and gets tight, however the plastic piece seems to be coming up with the handle and gets tight. I don't want to force it and break something because I will have to remove tile to gain access under the faucet.
Any help would be appreciated. Thanks

https://terrylove.com/pdf/t951pt-parts.pdf

 

[Tuttles Revenge]

when you unthread the handle, is there any portion of the adapter you could grab with pliers to try to hold it in place while you unthread the handle? Its been a long time since I've worked on that kit.. don't recall how they operate exactly at this point.