Delta Tub Faucet Huge dilemma

[todenbach]

I changed the rubber washer and spring on one side easily just like always on a Delta faucet. On the second side the nut and cartridge turn together. I stopped immediately since the cartridge is keyed to the brass part of the faucet that comes from under the tub. Turning a part that shouldn't move seemed like a bad idea.
The only part of the cartridge that is available to grab and hold is the stop. I am soaking the whole thing in penetrating oil but if that doesn't help I am at a loss. This is an individual handle Roman tub faucet. Any suggestions really appreciated.

 

[cdimarco1984]

Majority of the time you can take pliers and squeeze all around the nut that holds the cartridge in place and it will usually unscrew after that

 

[AAABathroomsOKC]

Or you can always turn the water off and take the whole thing out where its easier to work with. just a idea.