Yeah always try the 'drain battery' trick first. If that doesn't work, tape the cables together (unhooked from the battery of course) and let them sit overnight. Yer basically fully draining the capacitors in the modules when you do that. Once you start the vehicle, let it idle for a while to straighten out.
If that doesn't do it, I'm pretty sure a good scanner with relatively new updates, something that has bi-directional capabilities like a Snap-on, or Genasys should be able to pair the radio. I'm almost sure I saw it on a buddy's. Some of the Chinese scanners can also do stuff like that. So, if you know someone who has a scanner with those capabilities. Obviously a Tech-2 could do it too, but those are less common.