You would have to first add a secondary bank account on the bank page on your Wealth Account. Once added, you can drop a message to aw-help@kuvera.in with details of the bank account that you want to remove from your Wealth account.
Do Note: Removing a bank account will not update the bank details in existing folios with respective AMCs. You will have to submit a bank change request to the respective AMC/RTA for updating bank details in existing folios.