[The dman]

Goto admincp -> styles -> style manager.

Expand the private message templates section..

There should be a template called: pm_webforumz_popup_script.

Next, goto plugin manager.

There should be two plugins:-
Webforumz :: Better PM Notification Cache Template
Webforumz :: Better PM Notification Parse Template

All accounted for. But I'm not following you on how to do the following, where do I find pm_webforumz_popup_script?

Replace the contents of pm_popup_script template with the contents of pm_webforumz_popup_script.

Thanks

I imported as a product as opposed to a plugin