Search for "Ed Mika" , aka "ontarian" on various photo fora. He is the king of no-glass FD to EF adapters. He has instructional videos on you-tube for a large number of lenses - how to take apart FD mount and replace with his EF mount adapter. Cost is $144.00 USD or CaD, can't remember which.
I have toyed with the idea of getting one of the FD manual focus supertelephotos and adapting it. I can't decide if I truly have the 'nads to haul around 10 pounds of lens.
~2K vs modern lens ~13K.