I usually just go one by one and grab each vine as close to the base as possible and pull with a steady force until it pulls out. Try to get them to dislodge as close to the crown as possible as this will make thinning easier in years to come. If you don't get the whole thing don't worry about it, at this stage it's more important to get them thinned before they get a chance to start wrapping around each other. Once that happens they can cause you more headaches than not. You'll be fine.