I don't understand why anyone would want to pack or file mounts when using a set of adjustables is so easy, similar to the filler method but quicker and less messy:
Clamp rifle/scope in a work-mate, point at a plain card 25-30yds away, set your scope elevation to the same distance, fire a shot into the card to make a distinct hole.
Use the mirror method to centre the scope without disturbing the rifle. Look through the scope and note how far out from centre it was.
Loosen both mount locks to allow adjustment, move the cross-hair over the shot hole by using the up/down or left/right until they align perfectly.
Carefully lock off both mounts, look through the scope to see if it's moved off the hole, if it has then loosen again and adjust until you have the cross-hairs & shot hole perfectly aligned with the mounts locked.
Finally carefully load and fire another shot into the card again without disturbing the rifle in any way. Does the second shot line up with the first or has it moved?
If it's moved, adjust the scope mounts again and this time be more careful not to disturb the rifle/work-mate.