Hi,
I want to do approximately the same thing, but replace slashes with hyphens, so - instead of /. Total newb. Would really appreciate it if someone could tell me how to do that! 
Load and then select the files that should be treated.
Click on the toolbar button "Action (quick).
Select an action of the type "Replace".
Set the field in which you want to replace.
Enter as search string: /
Enter as replace with: -
Click OK.
Wow, thanks for the quick reply! Works like a charm.