Need to remove text but keep background.

 here is what I'm trying to do.

I have a scanned guest pass that is 2 color. The pass is in jpg format. although i can put it in any format necessary.

I need to change the "800" numbers on the pass. To the new number.

is it possible to remove them( numbers) and replace them, while keeping the background of the pass the same. if that make sense. I have Corel 6.

thanks,