How to safely bias Cayin A88T Tube amp

I know this amp has been the target of much talk on this subject, but does anyone have a step by step guide to biasing this fantastic amp? I realize there are some dangerous voltages in there, and to do the job, you have to take the back plate off and switch the amp on right? But, where do I take the readings from, once I'm in there?

I'm sure there was a post on here with pictures, but I can't find it for love nor money.

Kindest regards

JP