I never saw this post before today....I haven't wandered much out of Banter Hall until just this week.

If the vine is that old, there is most likely quite a bit of older, woody looking vine to it. We had a few grape vines at our old house..it was trained to grow on an arbor that went over our back patio. The vine was between 5 and 10 years old. Our first fall there, I was not educated in grapevine and I totally cut the entire vine back. I cut it with the sawzall

at about 6" from the ground. It survived just fine...tho it didn't grow much fruit that first summer then. So, you could do that and then as it grows in the
spring and summer, you can just pull it and twine it around the arbor. Then once you have it on your arbor, in the fall trim anything off of the main vine, leaving the main vine on the arbor. The main vine will get a woody look to it the next summer or the summer after that and it will be much easier to trim it the second fall because you'll be able to pick out the difference between the main vine and the year's new growth really quickly.
To keep the vine where you want it on your arbor, you should get some twine to anchor the main vine on the arbor and if you don't want the shoots that come off of the main vine to go all crazy on you, you should go out and check the vine every morning and evening and place the new shoots where you want them. The shoots and vine can grow as much as 12" in the course of one day!!! I was always amazed at how quickly our vines used to grow!