Homebrew_PCBs

I have used a sharp X-acto knife and scraped the copper off.if it is a small area.  For a larger area cover the traces with a marker pen such as  Sharpie.  Then use a little fresh  etchant on a Q-tip and rub over the area to be removed.  Depending on the etchant you use, it might take a while.
DuWayne
KV4QB.blogspot.com