It would depend. Your profile states that your mom has Alzheimer’s. Would the designated POA object to being dismissed? She needs to see a certified elder attorney. If she is aware of what she is doing, she can sign another POA document, designating a new agent. Her attorney could draft a document for her to sign dismissing the previous POA if she is competent to do so. Otherwise you would have to file for guardianship. Please see an attorney.
It can be rescinded through execution of a subsequent one, appointing some one else, or simply rescinded and rendered null and void. This should only be handled by an attorney.
The proxy would be notified as required in the original document, probably by certified mail, return receipt requested.
Another thought: 97 Year Old Mom raised the issue of competency when executed. Was there any indication that she was or wasn't able to understand the issues and consequences when she executed it.
You indicated that there is a "long story" and that your mother was "duped" into execution. I think this bears attention well beyond the issue of revocation.
There's no way I can check for past history though - your answers aren't enabled and a search on your name doesn't provide hits for any answers.
If she was not of sound mind when it was created, provide the documented diagnosis to the attorney, along with new POA a written time line of events and it should be invalid. Also, if this POA is dupping an at risk senior the attorney needs to tell you if law enforcement should be notified.
The proxy would be notified as required in the original document, probably by certified mail, return receipt requested.
You indicated that there is a "long story" and that your mother was "duped" into execution. I think this bears attention well beyond the issue of revocation.
There's no way I can check for past history though - your answers aren't enabled and a search on your name doesn't provide hits for any answers.