Larry,
Go ahead and take it to the upholstery shop. He does not need the windshield in to do any of what he will do. As a matter of fact, the windshield must be out to put in the dash pad anyway. Make sure that he leaves all the extra material on the windshield side of the pad, I allways like to make sure that the dash pad vinyl actually is captured under the rear edge of the windshield rubber body gasket. the vinyl will shrink over time and will show if not left long. Take a heat gun and form the extra material over the edge down into the channel tha the gasket sits in. I missed the second appointment to get my carpet done, and am still waiting to get it in.
Regards, John McGraw