Help !!!

I've downloaded a db, and made some tweeks to it, however I've just knocked something out on the FA cup, and it wont allow me to revert. (I saved before realising)

It is saying the maximum teams is 256, but I need it to be 1008.

I know this is possible, but I cant do it.

Is it possible for someone to help me please?

For some reason I cant get it to upload, so would need advise.

Thanks,