77 450SL - I would like to have some advice on changing the heater core. And please don't say "don't do it yourself". I don't have a MB repairshop within 250 miles. And, part of the fun it to get dirty right?

So, where is it, can the cores be rebuilt by a rad shop, and are there any absolute "DON'T DO'S".

Any advice is welcome, Saterday is the big day.

Mike
77 450 SL
87 560 SEC