Found these guides hidden in the depths of the release notes for IBM Connections 5 CR2.
Noted that the CR2 guide also has call-outs if you are doing a 5.0 > CR2 update.
Looks like the 5.0 -> 5 CR2 requires some extra SQL scripts against your connections database and some additional Content Manager requirements.
CR1 guide here
CR2 guide here
Thanks to IBM for some good material.