Ok, so I know this isn’t an issue anyone with half an ounce of sense is going to get themselves into but then I never said I had any sense…. I built a lab a while back and it’s been some time since I logged onto it, unfortunately, in that time I had managed to forget my SSO domain & Password.
Fortunately, I still remember my root password which gave me a method to recover!
The steps are as follows:

1. Log into the VAMI & enable SSH
2. SSH to your vCenter
3. Type shell and press enter
4. Type the following to show your domain /usr/lib/vmware-vmafd/bin/vmafd-cli get-domain-name –server-name localhost
5. Then type /usr/lib/vmware-vmdir/bin/vdcadmintool
6. Press 3 and follow the instructions….

Its really as simple as that