Hi guys it's been many years since the release of my female Scientists.
https://www.moddb.com/games/half-life/addons/female-scientists

Today I am attempting to rig a head onto a main body mesh but I can't recall how. It's been to long. Could any of you tell me again how it was done.
I checked through the old tutorial vids of back then but the solution eludes me.

This is what I did:

Importing my HECU head deleting it's bones and then importing the HECU main body_mesh. Now I can't remember if I had to parent the head mesh to the main body mesh or if I had to parent both meshes to the bones but I'm also getting a No bone selected error.

If any of you could tell me in simple layman terms what I'm supposed to do in chronological order I'm certain my memory will return immediately. It's just my uncertainty to know which step to perform when at the moment. Thank you

EDIT: I solved it. I just had to replace the head mesh and add the new head instead and combine the remaining meshes with the new head.