[ovirt-users] reinstall hosted engine vm (centos 6.6 -> 7)

Hi, I currently have Centos 6.6 engine vm running, the server it self is running centos 7 with oVirt. How I could get rid of the 6.6 Centos engine vm and update to Centos 7 engine vm ? I was unable to find any docs on how to do it. Thanks in advance. Br, Pete