Where is NAV2 with GTn750 & GTN650

[1v4n]

1st many thanks for a great plane

I am using a combo of GTN750 and GTN650, and i can't find the source for nav2? where can i adjust it?
NAV1 and RNAV switch is clearly switching vor1 between gtn and kns81 but where should be nav2?

Also is there maybe an exact guide how to use autopilot so it switches from gps to vloc? Is there an exact order of things which you should do?
Like on the last leg press APPR and than ATT so it goes to GS?