Where am I supposed to find EPiServer.BaseLibrary version 5.0.2000.15 which seem to be required to migrate between EPi 4.62 -> CMS 5 SP2?
Is it for download anywhere or am I to install some earlier version of CMS?
This library cannot be installed individaully. You need to install the entire version of the EPiServer CMS 5 to get the library.
Also read the below link for the migration from 4.62 to CMS SP2