To change the bank account your session fees are paid into, you will need to log into your Stripe account at https://dashboard.stripe.com/
Once you are logged in, click on Settings, then scroll down to Business Settings, click on Bank Accounts and Scheduling. Then click on the Edit button to amend your sort code and account number etc.
If you need any help with this, you will need to contact Stripe. You can contact the Stripe support team by logging into your Stripe Dashboard, and then clicking on "Contact Support" on the right-hand side of this page : https://support.stripe.com/