I shipped several square grand pianos to Malaysia, and the process
isn't difficult.

First, crate the instrument. You can do this yourself; just add 2x4s
on the base for the forklift and use screws to hold it together so the
contents can be inspected.

A crater can build the crate for you (try "cratersandfreighters.com"
or ask any freight forwarder).  You can then hire a freight forwarder
(I like KINTETSU).  They can pick up the crate and send it by air
anywhere on earth.  It can be picked up at any international airport
by the buyer or delivered directly to the buyer.

If you live near an airport, you can deliver it yourself to the freight
depot of any airline.  A "freight consolidator" can put your crate in a
container for shipment by sea.  This is cheaper, but not always a lot
cheaper!

Philip Jamison
West Chester, Pennsylvania