At the simplest, there's a Go-Around button that you push to engage
go-around mode. The autopilot then commands a pitch up on the flight director.
There's also sizable automation when the system is connected with a GTN750 or 650 navigator, including a coupled
go-around mode when executing a missed approach.
The Autothrottle computes and controls appropriate power levels and features an automatic take-off and
go-around mode that smoothly brings the turbine engine to max power in a few seconds.
Once the decision to go abort the landing is made, you should go into automatic "
go-around mode." The reason for it can wait, as can the CTAF discussion and explanation to your passengers.