I have a AIR-SAP1602E-A-K9. My question is do I have to install an antenna on all three antenna connections?

We just purchased a SupII+ to upgrade our 4006. Currently it runs CatOS 6.3. What's involved in replacing the II with II+. We don't have vlans or anything special. Just a couple of fiber runs to some closet switches on the gbic ports. Also, 1 span po...