How to replace heater core on 97 Land Rover discovery?

You need to pull both coolant hoses going to firewall. That will give you an approxiamate location. It will be sandwhiched in between ducting on int. Under dash in that area. You need to split the duct R&R and attach hoses. Replacement easy. Getting to it oft times a pain. Core itself usually around 30.00. You might consider paying to have it done or bypassing. (Just connect the hoses together)