To put this in simple terms, checking for myself and to help anyone else it is :
Plastic "cap" back onto the CPU
Duct tape around the edges of it
duct tape the sandpaper on a flat surface then rub CPU on top of this
apply light pressure with CPU/sandpaper
sand down until you see copper
brasso metal polish to get rid of swirls
clean thoroughly with Isopropyl Alcohol(?) using kitchen roll/cotton ear bud(?) until no dirt rubs off
Missed anything out or written anything wrong, just change it plase to help me an anyone else
For a lapping kit with glass you just duct tape the glass down to a flat surface, then duct tape the sandpaper on top of the glass
Picky I know but thought it might help some people having simple things cleared up !