Updating Garmin HRM-Run software (red belt)

I just received a replacement HRM strap (red) after my previous 1 week old hr strap refused to play nice with my MARQ Expedition.
As reported in the current issues topic, I have been seeing big running dynamics reporting dropouts.

Both the previous and the current strap came with software version 3.40 any ideas on how to update it to 6.60???