I tried a bit with a knife and no luck
I see the traces can be cut on the Proto Board - but how do I cut a trace? I tried a bit with a knife and no luck. Any suggestions? I have a Dremel tool if that helps.The holes are through plated so can I stick a wire down from the top and solder the wire from the top? The board will be mounted where I will not have access to the bottom for final assemblyThanks Much https://www.adafruit.com/product/1609
You need a scalpel or a Stanly knife. Make two closely spaced parallel cuts on a track and then remove the copper in between the cuts with the blade. Or you can use the tip of a twist drill turned by hand in the hole. A tool that does the same job, but better because the angle on the tip is more suited for the job, is called a "spot face cutter". spot-face-cutter
Use a 45° or 90° 'D' bit with you Dremel.Center the bit on the hole, advance the bit into the PCB until the trace is severed.
This is an example of cutting along the length of a track so you can use surface mount components with 0.05" pitch.
that seems to have broken the trace without needing to scrape traces off
I would double check by going over the cut with my finger nail, smoothing it down. Then check with the meter again.