Ok, here are some pics of the process, thought i had some in the build thread, but i don't so here they are!
First cut, I cut about 1/8" away from the seam line of the tail lights (look at the bed close, you will see the seam i am talking about) so i could remove the extra from the tail light section with ease.
Then i made my second cut, to take out the "excess" i took out 12" total.
Here is the extra, plus you can see the tail light section hanging upside down behind it.
Here is the tail section:
Then came the dovetail, this was a little harder and didn't turn out as well as i'd hoped, mainly because the bed i started with was a rust bucket, but i started by cutting about a 1/2" from the inside of the bed rail, the length of the remaining bed.
Second cut was the hard one, I used a chalk line to sort of get an idea of where i was going, looking back i think i would have chopped the fenderwells out completely and readjusted them accordingly.
Here you can see the bed has "dissapeared"
Here are two of it outside (i have since cut the bed to shreds and put tube in it's place.
Here are a few from when i finished up the tailgate for it. and what it sort of looked like.