Using external power and USB with Arduino Pro Mini 3.3V

I have a Arduino 3.3V 8MHz and it is connected to my computer via TTL lead and all is working fine.

I want to power project externally using battery connected to RAW pin - but I also want to use the USB TTL lead for receiving data on serial monitor.

I have used Teensy boards before and to do this this there is a trace to cut on board (so the Arduino not getting power from the computer USB.) Is there a simple way of doing this on a Pro Mini?
Grateful for any advice.

Andrew

You can carefully slice open the outer insulation on a USB cable and cut a section out of the power wire to create a "data only" cable.

yes -I'll do that - many thanks!