Just to close this out, I ended up copying the files to the new HD keeping the same folder structure using the copy program that allowed me to verify a good copy with a CRC check of each file. When I swapped out the drives in the PC, assigned the old drive letter (I use L: ), rebooted and started up LR it functioned as normal, no need to update location or anything (so I assume LR is only concerned about the drive letter in terms of location). Totally painless.