Thanks guys, I have long felt that it was impossible overall and have adopted the items mentioned. There is always some maintenance window, sometimes on the spur of the moment 
.
I've tried and haven't figured it out. If the telco's can't do it over years, I figure it can't be done.
I agree with Antares that you have to build some downtime into your SLAs to handle this. BTW, I've worked with 7 long haul carriers and 5 co-location/managed service companies. Not one of them has 100% uptime for the network over a year.
Oh well...
Steve Jones