You need to re-register the VSC to the vCenter server using the account that you want it to use.
Log onto the machine that's running the VSC software, and open https://localhost:8143/Register.html in a web browser. Enter the new credentials and click register. Your existing VSC configuration will be retained but the account will be updated. It's best to use a "service account" with a password that doesn't expire.
Note also that there is a bug that may cause the account to be locked out in AD. For a workaround, see https://kb.netapp.com/support/index?page=content&id=2019934&locale=en_US.