To unassign a club follow these instructions:
1) Navigate to the My Bag screen.
2) Tap on the club that you wish to unassign. If you have done this successfully then the club will be highlighted red.
3) Tap on the 'Remove' button at the bottom of the screen. This will bring a pop up onto the screen. Tap on the 'Accept' button to unassign the club from the tag slot. You will then be taken back to the My Bag home screen and the tag slot will now be vacant.