Document RHEV-H 3.6 (7.3) to RHVH 4.0 (7.3) migration after process has been verified. Part of this bug: https://bugzilla.redhat.com/show_bug.cgi?id=1376454
A quick note (for bug targeting purposes) that this functionality is provided as part of the 4.1 cycle, but the documentation for it would make the most sense in the 4.0 Upgrade Guide.
I don't see what there is to document, please reopen if you disagree.