How do you remove barrel from model 70 pre 64 Winchester rifle?

Answer 1

You're going to need some special tools for that. This is one of those things that really isn't in the range of things you can do with hand tools in your garage. The barrel IS simply threaded into the action, but you're going to end up mangling some expensive parts if you clamp it in a vise and throw a pipe wrench on the barrel. ...and after that, then what? You can't just screw in the new barrel. There will be issues with getting the notch for the extractor proprly aligned, and then you'll have to get the chambering and head spacing right, which will require reamers you'll have to buy. You really ought to consider going to a gunsmith, this is a serious project.