Many have been there and done that. Remove all the screws and the compression post. Cut the fiberglass tabs attached to the hull and remove the bulkheads. Use the old bulkheads as a pattern for the new ones. You'll need two sheets a of plywood. You can't get both bulkheads out of one. Finding the right ply might be a problem but in your area it's most likely available. It won't be cheap. It's highly doable DIY project. There'll be plenty of advice here. Good luck