Removing silicone

[Coralgurl]

Is there an easy way to remove silicone? I'm trying to repair my sump by placing a piece of glass over the crack, which will in turn will take the pressure off the original glass.

I need to remove some of the silicone and holy hell it's not easy. The sump is full and operating except for the cracked section, dry and clean. I've got Orca underwater glue which I picked up at WAIS.

How much silicone do I need to remove to make this work?

Thanks