If there'* no oil leaking from the pulley end of the nosedrive, the seal is probably fine.
You cannot get the nosedrive off an M62 without removing the SC from the engine, but it'* not a bad task.
First question is where are you located? If it'* Oklahoma as I suspect, you may not have a member near enough to help, but it'* not bad, and it'* actually quite fun.
It'* a one-day job at the most, but you'll need a few things:
SC outlet gasket
2 yellow coolant o-rings
Red sealant for the nosedrive (gasket maker)
one bottle of SC oil (get two, always have a spare)
Fuel injector o-ring kit
(buy all the above items from the dealer for about $60)
This might also be a good time to do the lower intake manifold gaskets. It'll only add a couple hours to the job. Also, remove the TB from the SC and use the procedure in Techinfo to clean the TB and MAF sensor at the same time.
The coupler can be purchased from www.zzperformance.com www.intense-racing.com www.rollingperformance.com
and the oil as well unless you get that from the dealer.
It'* straightforward, and there are many more resources and topics on this in Forced Induction. I'll move this topic there for you.