How do I replace the heater core?
Get a repair manual.
Hi damian! Here's a web site to give you a basic idea of how it's done. (http://www.diynetwork.com/diy/ab_talk2diy/article/0,2021,DIY_13696_3105967,00.html). It's a job only a contortionist would love. It's not terribly tough, it's just a painful job. This is probably one that you should probably give over to a pro if you value your sanity. If you decide you want to tackle it, head to your local library and check to see if they have the Chilton's for your Lumina (I'd guess there's a good chance they do). You are going to need one of these to see the best, easiest, and most efficient way to get to your heater core. If you can't find one at the library just call your local bookstore, part place, or Chevy dealer and see if they have one in stock. If you are going to do the job this wil be worth it's weight in gold. Good luck!
every time I shift it into a gear it dies I replaced the computer, cleaned the EGR but it still does the same thing that it did when I bought it from my friend. what should I do now?
Looking for a Used Lumina in your area?
CarGurus has 256 nationwide Lumina listings starting at $4,090.
Search Chevrolet Lumina Questions
Chevrolet Lumina Experts