Picked up a used computer and need to reset login password
Hello Genius bar! 
I have been a mac user for a few years now and am trying to get my dad to convert. He picked up a used G5 17" which has no install disc's and which is password protected. I dont know which version of OS X its running. I believe 10.3, but not sure.
I had tried the root login thing where you hold the command key and s key but was never able to get proper steps for changing the password.
I also tried to use my 10.4 install disc's but when i did this it told me that it cannot install or boot them. (Curious if this is because of a hardware requirements not being met, computer only has 256K ram.)
can anyone help me with this. I would love to just wipe the entire system clean but would settle for just being able to create a new password and go from there.
Thanks

I have been a mac user for a few years now and am trying to get my dad to convert. He picked up a used G5 17" which has no install disc's and which is password protected. I dont know which version of OS X its running. I believe 10.3, but not sure.
I had tried the root login thing where you hold the command key and s key but was never able to get proper steps for changing the password.
I also tried to use my 10.4 install disc's but when i did this it told me that it cannot install or boot them. (Curious if this is because of a hardware requirements not being met, computer only has 256K ram.)
can anyone help me with this. I would love to just wipe the entire system clean but would settle for just being able to create a new password and go from there.
Thanks
Comments
I had tried the root login thing where you hold the command key and s key but was never able to get proper steps for changing the password.
/sbin/mount -uw /
/sbin/SystemStarter
passwd root
That will enable the root user so you can change anything - you can disable it later. You can try using the name of a user that exists to see if it will allow you to just change the password.
If you don't get that to work, you can try:
mount -uw /
rm /var/db/.AppleSetupDone
reboot
Use the tab key when you enter pathnames to auto-complete especially when using the rm function. That should get you into the OS X intro setup, which should allow you to make a new account.