The only way to reset the settings is, I'm afraid, to remove the settings file of the specific tool.
For example, if you wish to reset the settings of the Duplicate Finder you must go to the product's settings directory (by default at C:\Program Files\jv16 PowerTools\Settings\) and delete the DupeFinder.dat
If you are unsure what file to remove you could also remove all the files from the settings directory, this would reset the settings of the entire application.