MetaMask has two versions right now: (1) Old UI and (2) New UI/Beta
1. Old UI
Old UI does not have support for token withdraw. The only thing you can transfer out of MetaMask Old UI is ETH. You will need to click the 3-lined menu on the top right (as shown below) and click on "Try Beta!". This switches your MetaMask version from Old UI to New UI/Beta.
MetaMask Old UI (menu on top-right)
2. New UI/Beta
The MetaMask New UI/Beta version does have token transfer ability. Clicking on the 3-lined menu on the top left (as shown below) prompts a dropdown of all the types crypto within the wallet. Click on the token you wish to transfer, then click "SEND". Enter your destination wallet and initiate the transaction!
MetaMask New UI/Beta (menu on top-left)