So I'm learning "The Ballad of Death" by Dj Ashba and there is one point in the song where I have no idea what he's doing.

Here's a vid. 2:56 is where what I'm talking about starts.

I think I've seen Van Halen do this before and when I looked up tabs for Ballad (I've been learning it by ear) it said to do a trill on the 10th and 13th fret and "chop the strings". Any links to vids that show how to do this would be appreciated