Ah ok.
So you previously installed an All-in-One setup following something like these instructions:
But this feature is deprecated in 3.6 and it should be dropped in 4.0
And you want to migrate this single host installation to an hosted-engine one, that for a clean new install should be done with something like this:
In your case you have to migrate and follow something similar to this:
but I think it is not so simple if you have at the end only one host to use....
You could export your VMs and the re-import them after migration and scratch of your hypevisor.
What Joop suggested is the rpm command (adding a final "m" to rp)
But I think that actually you are on All-in-one where the engine mgmt part is installed on the same machine that acts as the hypervisor.
Try to read the migration doc I pointed out and see if you can adapt it to your environment (I don't know which 3.x version it is...)
HIH,
Gianluca