I have read about the "double rescanning" method of removing old digital TV stations from memory, which involves the steps at http://www.dtv.gov/rescan.html
Depending on the converter box model, this method may not remove all old channels from memory.
The easiest way is to delete all channels in memory and scan for channels again.
Depending on the converter box model, this method may not remove all old channels from memory.
The easiest way is to delete all channels in memory and scan for channels again.