Hi there!
Looks like that page is password protected so I can’t view it. However, I’ve got a pretty good idea as to what you are talking about.
First of all, though, it’s important to note that all Event Rocket is doing in this situation is letting you add Events Calendar PRO’s existing calendar widget to a page via a shortcode.
So, really, this question would be better suited to the Events Calendar PRO forum since what you’re really asking about here is how to customize the calendar widget: the fact that you happen to be adding it via a shortcode doesn’t really matter.
There is actually a method you can use to disable this altogether – TribeEventsPro::disable_recurring_info_tooltip() – or else you could do something like:
add_filter( 'tribe_events_recurrence_tooltip', '__return_empty_string' );
The only downside to such an approach is that it will remove that text from everywhere, not just the widget – if that’s a problem you’ll need to do a little more work.