Just wire it to a case structure that inverts the pulses. That's a pretty generic answer but that's what you get when you post generic questions. Can you be more specific about your application and what you've tried so far?
A check box is a boolean. Use it to drive a case structure. Depending on the way this pulse is constructed, you should be able to mathematically invert it. for more help, you'll need to provide some details. Perhaps even attach a VI showing what you've done so far.
Something like this?