[ovirt-users] How to change the hosted engine configuration manually?

After an update in the cluster configuration, the hosted engine ended up with an invalid configuration (bios x machine type) and it's not coming up. I need to return the bios to legacy mode, but I'm not finding a way to correct the xml generated to turn the machine back on. The storage domain is iSCSI. Any help would be appreciate. (reinstall isn't an option).