How to change iCloud password on a remote Mac?

I use iCloud and Back To My Mac (BTMM) to access some of the computers I have overseas. Everything was fine up until yesterday when I had to change my iCloud password. I now have lost access via BTMM to those remote computers as they need to have the iCloud password updated in the iCloud panel in their System Preference (and the Back to My Mac option has to be disabled/re-enabled to have it restarted).

I have remote SSH access to those remote Macs (all running Lion and in one case Snow Leopard), so I have a working SSH shell on them. But I cannot figure out how to update the iCloud password that is stored on those Mac via command line. I can reboot them if needed of course remotely, I'd just need to update the password used for the iCloud services...

Having someone walk to those Macs, login with my account and have them enter the password for me is not really an option, as to do that I'd have to give them both my Mac's account password and my new iCloud password, which is not going to happen :-) In addition, some of the Macs are used by my parents and in-laws, with their computer skill being limited to knowing how to open Safari and the Mail app. They wouldn't be able to help in anything technical.

So... is there another solution other than buying a plane ticket to go overseas and do it myself?