How do I unpair a wireless keyboard from an iPad?

I have just bought a Mac Mini but it won't recognise my wireless keyboard which was previously paired with my iPad. I don't have a wired keyboard to get into System Prefs. Is there any way I can unpair the keyboard.

I've unpaired it on the iPad, removed the batteries, turned off the iPad, paired the keyboard to my MPB and then unpaired it....everything I can think of basically...but the keyboard keeps looking for the ipad