All the PDKs I've ever received came with some install docs that tell you how to point at the various pieces (often giving you template cds.env, cds.lib, .cdsinit and basic install info). More meant for Chief Cad Dude or local sysadmin, than "regular users" as you'll probably want to put some of this in places with permissions that prevent clueless users from making a mess of what they don't own.
It would be surprising if you received any PDK (aside maybe from the open source one) without interacting with inside-Skywater people. Might hit up your point of contact if you really can't find the installation info down in the tarball.