1. Select the 'Exchange' tab on the toolbar
2. Select your collection of interest
3. Navigate to the Exchange section in the top-left of the page
4. Click the arrow under 'ETH' to ensure GBT balance is on top
5. Enter the amount of GBT(s) you'd like to sell
6. Click 'Swap', then 'Confirm Swap'
7. Click 'Confirm' on the Metamask pop-up to approve access to GBT
8. Click 'Confirm' on the next Metamask pop-up to initiate sell