How can I perform a token burn?

Burn

Burning tokens will remove them both from the circulating supply and your selected Investors' Balance/Wallets.

First navigate to "Actions"  and "Burn", you can then remove tokens directly from a particular investor

Like all actions you can view the status of this in the Servicing Activity section.

Once the transaction is confirmed on-chain you will see the Circulating Supply update on the dashboard. You can view the status of that particular transaction on the Dashboard under Servicing Activity.