Here's a link to the procedure on Clark's -
DME Control Unit Chip Installation (Including KLR Chip for Turbos)
I've seen pictorals but can't remember where. Maybe the Lindsey Racing site?. Here:
http://www.lindseyracing.com/LR/Parts/CHIPCHANGE.html
Basically, you pull the DME out - it's under the carpet in the passenger side footwell, then open it up. You pull out the old chip and install the new one.
Make sure to take proper anti-static precautions - ground yourself, and to the best extent possible, don't touch any of the electrical connections or pins with your fingers.
Static electricity can kill electronics. Bigtime!