need help/advice on cutting out rockers..

[lakailimited06]

whats up guys, i want to either cut out my rockers and try to reuse my JCR's and just move them up or weld in some 2x6 like some guys do..i really like the JCRs and will try and use them first...

i pretty much know what i have to do i just dont know what i "sholdn't" cut..whats going to weaken the unibody/floorboard?

heres some pics of under the WJ:



looking for something like this:



im just not sure where to start...i have a few free saturdays coming up id like to bang this out before rausch if possible...