loading a new OS on an existing machine?

[TimwaTumble]

ive been given a ppc mac mini running 10.3.9, its usable but i dont have the admin password, nor can the previous owner remember it or find the original disc so i cant update it over the web.

ive got a copy of 10.5.6 and would like to install it and start fresh.
how do i go about doing this? once the new os is installed will i have the problem of the old password? or will it be a new machine?

[trevor]

If your OS X 10.5.x install disc is a (black colored) full retail disc, NOT a (gray colored) disc marked for some other specific Mac, and not an Upgrade disc, and

If your Mac Mini G4 meets the minimum system requirements (such as a the amount of memory) for Leopard, and

If your Mac Mini G4 has a DVD drive (assuming that the Leopard Install disc is on DVD, which 99% of them were), then

Boot to the OS X Install disc by placing it in the computer and holding down the 'C' key on startup until you've booted to the DVD. At one point, after you've agreed to the EULA, there's the option for a custom install. Take that option, and do an "Erase and Install", which will erase the hard drive before making a competely clean installation of OS X 10.5.x on the hard drive.

Then, you will have what amounts to a new machine.

Trevor