BlackBerry unlock/reset

[Mark]

I've 'acquired' an old BlackBerry to temporarily replace my (lost) iPhone, but it's locked and I have no idea what the password is.

Is there any way to do a factory reset? I'd like to get rid of the password and any user data. If there was free stuff on there I might want to keep it, but since I don't know, I'm happy to never know and just blitz the lot.

I did find a MicroSD card in the back, if that's any help.

PS - Unfortunately I've no idea what model it is. BlackBerries wouldn't normally be my 'thing', but under the circumstances.