I would guess that the hole on the bolt head side is large enough for the compression tube to slide out. If you drill out the rivets on the bracket you should be able to remove the bracket and bolt together. If this is not the case, I would vote for cutting the bolt head off and enlarging the hole to slide the tube out. Trying to hammer or press the bolt through will likely damage the mast before the bolt comes out.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
John USYacht 27 "Cora Lee"