I was going to install an Oil Pressure Gauge. Based on the following link,
http://www.grandprix.net/upgrades/oilgauge.html

It states to drain the oil before removing the stock pressure switch. Is this true? I just changed my oil a few days ago and I hate to go through the hassle of changing it again.

Are there any other tidbits I need to be aware of that are not listed in this link?

if you dont, you will more then likely get oil pouring out of the hole... you can eather put a pan to catch the oil, and just top the oil back off after you put in the new one, or drain and put new oil in again

Drain it.... its too much of a pain in the butt in first place... having oil pouring out will just make you go crazy.
I should post a picture of my rig down by that area.... got a few brass T's, extention, oil line to the SC, and oil pressure sensor. bleh.

Few other questions:

You used teflon tape on the threads?
Any other annoying items to watch out for?
Is your gauge hooked to the dimmer?

If you just changed your oil I'd wait till your next oil change then do the mod. If the sender is above the oil pan I'd say let the car sit a couple hours and just have a rag handy. I'm not really sure where the sender is so take my advice for what it's worth. But a little logic goes along ways.

Yea, I decided just to place the interceptor and the non-functional gauge into the a-pillar now. The next oil change (June or so), I will just unscrew the A-pillar and install gauge then. If I start to get annoyed by it, I'll do it sooner.

I've seen a few pics on where it is located. It is very close to the oil filter. The sender unit for the gauge doesn't look like it fits but several sources say it will.

Why don't you just run the wire down there and install the sender later?

Don't be scared.

The amount of oil loss can be soaked up by one rag. I make a bigger mess taking off my oil filter than I did pulling out the the sender.