Raid drive failure

I finally got my RMA'd KT7A-Raid board, got my server set up with a mirrored Raid. I have a single drive with the OS on it, and a pair of mirrored 40 Gigs for data storage. One of the 40's failed. I will be heading to the store (The BB word, unfortunately, dont want to order it at work tomorrow and wait till next weekend to fix it. No time during the week) to pick up a new drive. Anyone ever replaced a failed mirrored drive and are there any tricks I need to know.
Thanks
Jim

Turned out to be a piece of cake.

Jim