It is easy to change out the crystals. You have to remove the crystal from the transmitter and receiver and replace them with another frquency crystal.

You can't select the frequency on the transmitter. I think (not totally sure) that the Airtronics MX-3S is able to change frequencies.

Just upgrade your radio to a 2.4 GHz system

http://www.amainhobbies.com/product_...ducts_id/16275

Here is a review:

http://www.rcgroups.com/forums/showthread.php?t=802367