Can we take over administrating our own property anytime and replace the present administrator who is not an heir?

My grandmother inherited parcels of farmland. The land titles were under the ownership of 4 people - my grandmother and her 3 siblings. They are all deceased. Our problem is there is an administrator that the 4 farmland owners mentioned have appointed when they are still alive. We know and have proven he had been dishonest and deceitful to us that is why we are planning to remove him.

My grandmother left 3 children who live in the Philippines, my mother, and her 2 siblings. My mother and I are now planning to move and live there and start managing the farms.

Can we relocate and live in the property and replace the existing administrator without any problem? We want to cultivate it ourselves this time to generate more income to all heirs because we believe we are not getting the right amount of share that we are supposed to receive.

The majority of the heirs have decided for my mother to replace the existing administrator. Can we just go there and take over as the new administrator without any problem? Or we would need to show a SPA from all the heirs or at least a signed letter of authorization perhaps?

What are the rights that this administrator can use against us?

We would like to know the options available to us and we will greatly appreciate any advice you can provide.

Thank you so much in advance.