S1200BTL BMC / RMM4 factory reset

It seems that a long time ago I enabled LDAP authentication on my S1200BTL's BMC / RMM4. Clearly the LDAP setup I had then no longer resembles what I have now and I can no longer login to my BMC. How can I either disable LDAP authentication on the BMC or just completely factory reset it?

I've used the setup and ipmitool to change and enable built-in users but this doesn't let me in.

I've also tried to update the firmware with the "-setdef" flag but this doesn't appear to do what it claims.

Resetting the NVRAM doesn't affect the BMC.

Any guidance would be appreciated.