Token outputs have satoshi values, usually 546 satoshis per output. In order to unlock the satoshis being used by token outputs, the tokens must be destroyed, this is called burning tokens.
Memo does not currently support burning tokens. Satoshis used by unwanted tokens on Memo will remain locked. Users can send tokens to another address if they do not want them.
Alternatively, which is not recommended by Memo, your private key can be loaded into another application that supports burning. See Import Private Key Other Applications for details about the risks.