If you mean to update them to 2.4Ghz, then you have multiple options and they're very affordable.
Here's a link to a conversion module that will fit your radio.
http://www.alofthobbies.com/jr-trans...ry-module.html
You can also get a Spektrum module to fit your radio, but as far as I know, JR is not selling a DMSS conversion module.
Good luck,
Pete