What can you do if an elder does not want the person that the court appointed to be your Guardian?

imo , if the court has already appointed a guardian they have thoroughly looked at the alternatives and made an informed decision . i think it would be difficult to have the judges decision reversed for any perceived reason . any attempt would be an expensive exercise in futility and the court would likely deliberately drag the process out to squelch the argument .

From the information you provided I doubt the court would consider a change in guardianship at this time. The only reason I could think they would change it is if the appointed guardian was remiss in his/her duties. POA is very different than guardianship. What emjo wrote is true. Your partner can only appoint a new POA if he/she is legally competent to do so. Since there is a guardian at this time, I suspect that your partner's competence has been in question in the past. Tell us a bit more and someone may be able to help.

If the elder is "incompetent" -(my interpretation of "in confident") they cannot appoint a POA. (my interpretation of pot), POA can only be appointed when a person is competent.
As far as I know, as Jeanne has said, any change in guardian would have to go through the courts, and there would have to be a very good reason for a change in a court appointed guardian. Also, I suspect it would be quite expensive.
More information would be helpful.

Could you expand on this a little bit? The elder has dementia and has a court-appointed guardian. And the elder doesn't want that person to continue as guardian because ... ??

Does this elder with dementia have a new "partner" (as in domestic partner)? Is that who the elder wants as guardian?

Any change would have to go through the courts. But you may get some more specific responses if you explain the situation in a little more detail.