Atmel studio 7 development question

How to use atmel studio 7 development watchX?
How to settings external tools when ISP watchX?

Maybe this link helps

This method I have tried is fail, but using the arduino uno development platform is feasible.

You may need an ISP programmer and watchX Arduino Accessory in-order to reach the ISP pins. Once you flash the watchX with ISP you will lose the Arduino bootloader. Not a big issue, you can re-flash it with an Arduino and Arduino IDE.