Some years back, I found myself in this very same place, only I was
in a customer's very fancy living room, and tipping the piano over was
not an option.

Solution: I purchased a box of drinking straws, the big size ones used
for milk shakes.  I removed the piano action, which is a very simple
thing to do on a Ampico grand piano.

I shoved the end of each push rod into a drinking straw.  Then I placed
the action stack on a couple of crates on the floor, directly below
where it was to go.  I was then able to easily bend each drinking straw
and stick the end through the proper hole in the key bed.

Next I carefully raised the stack into position and fastened it in
place.  An extra pair of hands is wonderful, but you can do it alone if
you must.  The drinking straw "extensions" guide the actual push rods
easily into place.  Once everything is made secure, just reach in above
the key bed and pull off the straws, and reinstall the piano action.

Just one more of those little tricks you learn on the job when trying
to "save the day."

Best to all
Ken Vinen, Stratford, Ontario, Canada