In Halion, how to adjust velocity for all events

This should be a simple one for the Halion users, I don’t have access to a lot of literature resources at the moment. In Halion, I select all the hi-hat events in a particular track, how do I uniformly adjust the velocity of all of them at once? I can select them all, but can’t adjust them all at the same time.

The Halion forum is here

thanks