To log into VA.gov using your existing My HealtheVet account, click the Sign in with My HealtheVet button on the VA.gov sign-in page:
Enter your existing My HealtheVet user ID and password to continue.
The next page will notify you that an ID.me account will be created. Enter the email address you'd like to use for your ID.me account, and click Continue. (You may use the same email address as the one associated with your My HealtheVet account.)
Follow the prompts to set-up multi-factor authentication to complete the process.