Heater Core on 1991 Buick Skylark

Do I need to remove the dash to replace the core?

2 answers
Yes. Removing the dash will be a requirement here. Its no small feat, lots of connector points and easy to break things.
I believe you do. If your going to do this yourself, get a good repair manual first, read up on the job before taking on such a big repair.
Go to http://bit.ly/alldata_repair_manuals or try http://bit.ly/mitchell_repair_manuals_online