When you unbond your tokens from a validator, you will not receive them back to your INJ balance on Injective Network until the
UnbondingTime completes. Injective's
UnbondingTime is 1 day (24 hours), so you will have to wait for 1 day to have your unbonded INJ returned to you for further action.
From the Delegations section, find the validator you wish to unbond your stake from, and click Unbond from the Actions column.
Sign the transaction in metamask to unbond your stake.