Valve 3 Stem Seals replacement (Gen 3)

Dear all,

I would like to replace my Valve stem seals but have yet to find a thorough step-by-step guide to do this. I am the kind of person who needs to be told about every nut so if there is a video out there that shows this then even better. Basically, I'm just asking for the same advice you fine people give about other procedures except it's for the Valve stem seal replacement. Many thanks.