How to change tripod head type

how to change tripod head type? HOw do you remove a ballhead from a tripod? Maybe you want to put a fluid video head on your tripod, or just upgrade the current ballhead. Once i located the screws I could not remove them with a simple allen key as they were much too tight and i had no grip. I found a tool that made the task really easy. A regular screwdriver could not get me close enough because the center column was obstructing the operation.