No problem! Monthly members just need to head to their Member's Area here to transfer their home gym. If you're less than 5 working days away from your payment day, you will need to wait until after the payment has been taken to make the change.
If you move to a dearer gym, an extra amount will be added to your next payment to cover your access to that gym for the rest of your payment cycle. The exact amount will be confirmed in an email after you've made the change.