bad news, i'm afraid.
there's no real way to easily replace the old clips with the new ones.
it will pretty much be a manual replace.
there are ways to automate the process.
i have done a fair bit of that using QuicKeys (a macro application)
it's still slow and arduous, but not as slow and arduous as doing it completely manually.
the process i've used involves a series of macros that do a search & replace based on the picture TC.
this often means you have to do one reel at a time, unless you have less than 25 reels,
and have been diligent in incrementing the Hr code every reel.
also, remember your picture cuts don't necessarily match your audio cuts.
write back if you want more info.
cheers,
nick