Yes, that VG will work just fine.
As for "how much", that's entirely up to you. What I would do is get a clearo or tank and fill it with 1ml of your liquid. Then just one drop of the VG. Mix it around really good and take a few puffs to work the old mix through the wick to get to the new blend. If one drop isn't enough, add a second, and so-on until you get to the point you want.
Then you can scale that to the remaining amount in the bottle. If you've got 25ml left in the bottle, multiply the number of drops by 25 and add that amount.