1) You can update your payment method on file by selecting 'Loans' on the homepage of your account. 

2) Select the arrow under 'View Details.'

3) In the Repayment section, you would see one of two different options. If you had connected your bank account when applying for Basis, you would select 'Change Bank Account.' If you had connect your debit card when applying for Basis, you would select 'Change Debit Card.'