It's a straight swap for the front. I did it on my bike. The hubs are the same on the front. I don't remember if the GL1000 is dual disc. If it is, you'll have to figure out a different spacer situation. There's plenty of posts about that for people converting to dual disc. I already had a dual disc setup with a stock CB750 wheel so I didn't have to make any changes. The rear, however, is a shaft drive hub so you'll need to re-lace that wheel.
Coincidentally, I have a 1975 GL1000 rear wheel that I need to get rid of. Please PM me if you are interested.