Thanks for joining the discussion here in the Community!
Migrating the existing balance is quite simple. When you set up your new bank account, the system will prompt you to enter certain pieces of information, such as a name and opening balance. The opening balance is where you'll input the balance of the existing account.
Note: Since your existing bank balance is in CAD, ensure you've properly converted this value into USD funds.
Once your new USD account has been set up, you can make the existing account inactive. To do that, click the small Pencil icon appearing on the bank account name > Edit account info > Check off the box next to "Disconnect this account on save".
If you have any other questions, please let me know.