First off, whatever Dell tells you fight them tooth and nail on it.
As to your question, I do recall a website that sells replacement screens and has detailed instructions to install. I will try and find it.
Edit:
http://www.screentekinc.com/ is the site that a guy at school refered me to a year or so ago. I didnt end up doing it, so I really can't tell you how positive the experience would be.