Problem with a bolt subframe bush

I have a big problem. while replacing the Subframe bush, a screw was broken.
Anyone know how to deal with it?
Is there any access to the thread?

Start spraying the remains with some penetrating fluid, my attack would be then to get a drill bit that will just enter the locator to dimple the remains to allow you to center a drill so that you can start opening up a path for an easy out.