I should have said "stack," not "piano" [in 010827 MMDigest].
Here's the corrected paragraph:

It can be easily removed from the rotating arms, because they are just
captured on plated, headless balance rail pins and can be sprung off
and away from the tray.  To remove the whole system, all that's needed
is to untube the expressions and function tubing and the 3 supplies.
So even that is easier than the way the factory envisioned it.  By
swinging the tray down, you can reach the tubing easier, untube the
system from the expressions, remove the player screws, replace the
tray, spring off the radius arms, or lift the whole thing out as a
unit.  The radius arms will stay connected in the sides of the stack,
away from anything else.  They do not interfere because they are flat.
And raising or lowering the stack doesn't affect it.

Craig Brougher