Hi
depends how bad yours is, changing a bulkhead is dead easy, I have done a couple now and its a nut and bolt job, the only thing to watch out for is that if you choose to do it the 'leave everything attached' way its pretty heavy and you'll need a couple of mates over to help, it is much faster to do it that way though. My bulkhead on the defender was made MOTable with a quick repair patch and used for another year while I sourced a replacement one and took my time blasting/welding/modifying and painting it so when it came time to swap it took me and my wife a day to do it, not working particularly hard, depends how confident you are mechanically?
Mike