UFO guide pin relube, how do you do it?

[Bernie Benz]

Doing the biennial brake fluid flush on my cars, an opportunity for  
close inspection while the gravity flush is running.My ’02 A6 had  
begun to squeal just before coming to a full stop under light  
braking. Noticed that the front pads were showing more inside VS  
outside wear, 4mm VS 6 mm pad material remaining. A sure sign of  
guide pin problems. Pulled the guide pins one at a time (7mm Allen on  
the FNR60s) cleaned and regreased, front and rear. Problem solved.

I’ve not found any obvious or simple procedure for doing so on the  
ATE UFO calipers, Have you?