I recently replaced the one on my T1i, and it is a piece of cake. Here is a paste from the email I received asking about how to order the replacement:
If you feel comfortable manually replacing the monitor cover yourself,
you can order parts from our Jamesburg Parts facility.
For the price and availability of parts, please contact the Jamesburg
Factory Service Center below and select the appropriate prompts for
ordering parts:
Canon Factory Service Center
100 Ridge Road
Jamesburg, NJ 08831
Phone: 800-OK-CANON (652-2666) and ask to speak with a Jamesburg Parts
Representative, or you can call them directly at (866) 481-2569
Business hours: 9 AM to 8 PM (ET) Monday to Friday
Make sure to order the double sided tape to go with it! My cost with shipping was just under $25 and I had in in 3 or 4 days. Everyones says that a suction cup will pop the old one right off, but I didn't get to try that, mine was shattered.
Hope this helps!