Short wide bed cut down from long bed

[choctawchevyclassics]

First- I already have a short bed frame. I am interested in cutting down the BED only. I have heard that cutting a LONG BED into a SHORT BED is not that big of a deal. I have (2) LWB's with metal floors that are both pretty decent beds. I have been trying to buy a short bed for about 2 months. I have WTB listings on Craigslist in OKC and in Tulsa. Sorry I am not going to pay $1000 for a bed that still needs to be worked.
Can anyone point me in the right direction for instruction on this?
What do I need to specifically watch out for?

Also I am going to have lots of extra parts once I start tearing into this. I'll be posting later.

Thanks in advance.