I need some help with a WD Passport usb drive I have attached to our NOWS

Initially I installed the drive and created a mount point successfully.
However, when I started backing up our GroupWise system to the drive it
crapped out at 4gb since it was formatted as a FAT drive. I removed the
drive and reformatted to NTFS from my XP laptop. I attached the hard back
to the server and created a new mount point. However, now when I try to
copy any file to it I get a "read only" error. I tried adding WRITE rights
in the GUI but I get an error on that.

How do I remove the old mount point?
How do I make the new mount point read/write instead of read only?

Thanks so much.