Flatten

[glorybound]

I come across this often, but I don't have a good way to do it. The red is the driveway, which I need to flatten, and the green is the grass, which needs to stay connected. I attached the red to the green, select just the red and flatten, but the green doesn't move with it. How do I flatten the red and have the green stayed connected?

[glorybound]

Okay, I need to weld first.