How can I replace a hard drive running BootCamp?
It turns out I was going down the right path...or at least it "works".

Here's the steps I took (following the link I posted in the OP):


Format external hard drive as extended (journaled) inside OSX
Export Boot Camp image using Winclone 2.2 (free online still) to an external HDD in a folder on the external HDD.
Turn on Time Machine and use external HDD as backup volume. Wait for Time Machine to copy all the files from the internal HDD to external HDD.
Eject Time Machine volume and unplug external hard drive.
Swap internal HDD with new HDD. (this part will be based on which drive you bought.  I got mine from OWC/MacSales and they have videos to help with the install.
Boot from Snow Leopard install disc (hold down options key and choose the DVD). (I originally didn't have one so I ordered one from Amazon with Prime overnight.
Select "Disk Utility" in Utilities after boot and format the new hard drive as Mac Extended (journaled).
Select "Restore System from Backup" in Utilities to copy the system and user files from external HDD to new internal HDD.
Reboot with OS installed on HDD rather than install disc.
Launch Boot Camp Assistant to create a new Boot Camp partition on new hard drive.  Here I chose a very large one (bigger than the original backup) since I needed more space...the whole point of the HDD upgrade.
Import Boot Camp image from external HDD to new Boot Camp partition on new internal HDD using Winclone.