How to adjust geometry of Impact Model?

Deke

So I have the Impact model which has a horizontal trench and a vertical bashed depression in a wall.  What I'd like is to move that vertical part to horizontal. This way the trench would lead to a pit. Unfortunately these elements are not separate but the same geometry. Is there anyway to make that adjustment? Perhaps it's possible to highlight one leg of this L-shaped geometry and deletes or turn off visibility?

Richard Haseltine

Which set is this? Point of Impact https://www.daz3d.com/point-of-impact has a trench, but that already ends in a pit.