How do i completely restore a mac mini g4 10.5.8 without install DVD
I have a used Mac Mini g4 running Mac os X Leopard 10.5.8 wehn I bought it off the person I got it with their name, like when I start it up and on the loginscreen it says "So and so's mac mini" I just want to completely restore it but it didnt come with Install DVD. Thanks.
Mac mini, Mac OS X (10.5.8)