If your 25 is like my 23 . . .
then it should not be a problem. I just removed the CB from my 1980 Oday 23. My boat has a shoal keel which I assume yours has also. Raise the boat on a lift so you can get to the bottom of the keel. Toward the forward part of the keel, on the bottom , there are two screws on each side. Unscrew these and remove the metal plates. The plates are holding wedges in place. I had to pry the wedges out. (They were held in place by some sort of sealant.) You do need to have someone support the CB. When you remove the wedges, the CB will drop down. The wedges are holding up a nylon dowel which is the front pivot of the CB. In talking to Rudy, from O'Day, I found out my CB is not original. It has plywood in it. Oh well.Good Luck,David