Much of it depends on where you are going to link it and how you wish it to be linked. For example - are you paying a bill with another non-USAA account? Are you wanting to transfer money between the accounts? It's all on the screen where you would do the specific transaction.
Please call a service representative to walk you through your specific concern. You can reach a service specialist at 1-800-531-8722
I want to link a local bank with my USAA bank to make deposits more convenient. I have to drive 17 miles to make a deposit into my account through a UPS Store, then 17 miles back. Thats 34 miles just to deposit a check!!!