How can I turn off Erase Destination Drive

[tmackinder]

I am trying to restore a drive from an image on one USB drive to another blank USB drive. The Image was originally done in Disk Utility. I can set the source and destination fine but the option During copy is grayed out. The reason I am trying to change it is because when I go through the process Super Duper erases the disk I see it unmount on my desktop then remount on my desktop but then I get an error at that point. So I'm thinking that if I can get it to not erase the drive During copy but rather just start right away at restoring then it wont give me the error.

How can I get the During copy option to unlock itself?
Any help would be appreciated.
Troy