Where are they located?
If they are right at the outlet, it's pretty simple. 4 bolts and the come apart (make sure to fully drain the tanks of course before pulling the bolts).
If they are remote (operated by cable), it can be more challenging getting to them (often they are hidden under the underbelly covering with no easy access) but once you have access it's not greatly different.
While I wouldn't discourage lubing them, regular use is probably the best way to keep them operational.
Tammy & Mike
Ford F250 V10
2021 Gray Wolf
Gemini Catamaran 34'
Full Time spliting time between boat and RV