To edit or change your funding source:
First, open your Qoins app. Click on the Settings tab (little person icon) at the top left corner of the app, then select 'FundingSource', then press "Change my account". You'll have the option to select your bank from the list or search for it in the bar at the top.
You can also link your funding source manually via routing and account number by typing in "searching" in the search bar and then clicking the "Connect your bank manually" button. Follow the prompts to see how this process works.
Once you've successfully linked your new funding source, withdrawals will begin to come out from this account and not any previously linked funding source.
You can view the tutorial video that shows the process here.