Though changing service account is not regular practice,I have recently encountered an issue and wanted to let you know the procedure to change the same using admin portal.

Logon to the Horizon Cloud here using the ‘My VMware’ account credentials and navigate to Settings > Active Directory and you will see similar to:

Created a new account with permissions as below in AD, for this demo I have created new account named captain-join1

• List Contents
• Read All Properties
• Write All Properties
• Read Permissions
• Reset Password
• Create Computer Objects
• Delete Computer Objects

Click on pencil icon next to domain bind as shown:

In Edit Active Directory page, replace the Bind user name with newly created account / password and click on Domain Bind.

Provide the domain join credentials and ensure there is a green check next to Join user name.

Thats it, Thanks for Reading and let me know by commenting below if you run into any issue.