The kill-dry would be used if you are using a parallel effects loop. If you are using an amp with a serial loop, you shouldn't need to use that function. Siimply use to cables to run into the effects loop of the amps send and return into the outputs of the g major. Its pretty simple, if you have no sound coming out, you have the cables hooked up backwards, just swap them around. Once you get the sound coming out, you'll have to spend some time tweaking the effect levels and getting them set right. Is you're amp a parallel or serial loop? If it's serial you'll probably only have one knob on the amp to adjust the level of effect coming into the amp itself. Adjust that to your preference and tweak the G major from there.
