Galaxy S3 mini i8190 hardware reset manual:
As we all know the new galaxy s mini stock recovery cannot be accessed by any key combination except a few modification is done.
which means out of the the normal volume up + home + power to access recovery and wipedata/factory reset will not work.
I assume you have too many pattern attempt of forget your passcode and need to reset.
simply download this i8190wipe.zip
open odin and slect it in pda
enter download mode as usual with volume down +home and power
connect to pc and make start.
all should be done.
Note: all data will be lost.
thanks to xda.