What is done when a power of attorney is left to both siblings jointly but one decides to become uncommunicative?

In reviewing the New York Times, I came across the following article in the  New Old Age section.

What is done when a power of attorney is left to both siblings jointly but one decides to become uncommunicative and “checks out,” not participating in decision-making, handling estate matters or caring for a parent with dementia? Does the sibling left with shouldering the burden really have to go to court to get the other sibling’s name taken off the power of attorney?

The answer, carefully review the document to see if there’s any provision that allows one agent to remove the other or otherwise describes a process for handling this type of situation. Or, if nothing in the document helps, the next alternative is to look at the state statute regarding durable powers of attorney, that may addresses this situation.

If neither of these approaches helps, the only way to change an existing legal document is to go to Court.