Swapping Memory and SSD's between two MacBook Pros

I already cleared it With Apple that the memory from my 2.0 GH Quad 4 MacBook Pro will run on my just purchased 2.4 GH Quad 4 MacBook Pro. I bought the faster machine with less RAM and will upgrade it to 8 gig by swapping with the 4 gig on the new machine. My question is about some details of changing the memory:

1) Should I disconnect the battery? It looks like I may be more likely to touch the motherboard with all the handling needed to remove the battery and replace it, versus grounding myself and getting right to the memory. Your thought?

2) What is this Opt+Command+P+R command through three boot cycles? I heard (not from Apple) it forces a restart on the memory? What's that all about?

I have swapped drives before and feel pretty confident with that. I will however need to take the new PC to the Apple Store since hey have pointed out there is no way for me to get Lion on that drive without their help. So that's my plan for after I get the hardware swapped.

Here's a question, after the hardware is installed must I not turn on the PC since it will still be formatted with Lion from the old machine? Should I format the drives before taking them out of the machines? I really do not want to load the machine with an OS that's not configured for that exact machine, and intend to give them each fresh install of Lion.

Thanks,
newbieweb