Not sure if eveyone know this or not but I just it out after speaking with Stuba. 

If you have a booking that you have paid for and are outside fees and need to change it. You dont have to cancell and pay the 1%. 

If you add the new hotel that you need for the same guest in manage booking, then cancel the other booking within the same booking number it will just calulate the differece. Just saved me $200 in what would have been a 1% charge to go onto my card then rebook