Floor and transom replacement

[Dmubarak71]

Hello! I’m a newbie boat owner I just got a stratos 269v but hadn’t realized the floor had some soft spots. Towing it home we had a horrible storm and the next day I came out to go over the boat and floor was mushy! Started to pull carpet and floor needs replacement but I have no idea if I should cut it out as I fear cutting the transom or other supports underneath. Could anyone please advice me what to do. I know I was a fool to buy a boat with no knowledge but we all start somewhere.