how do I get a Cisco Explorer 8640HDC to work with a sling box M2?
You have to be a LOT more specific than that. Why can't you get it to work ?
for one thing it is not on the list of routers supported
Routers supported ?? Don't you mean TV boxes ? If it is just that then check out this thread: https://community.sling.com/message/10363#10363
try the Cox 8242 HDC. The remote seemed to work for me.
Retrieving data ...