I fubar'ed it

Macbook Pro 2ghz Intel Core Duo Version 10.5.6

Hi guys, i was attempting to change my short and long username using these instructions - Changing the short username in Leopard | Mac OS X | Macworld

I went the Full monty approach as it didnt seem difficult at all.

I lost My Admin privy. So then i went to searching, i found this fix
Leopard: Administrator privileges gone - Mac Forums as i would just rather set everything back to stock on this machine as this used system did not have a disk with it.

I tried Apple/cmd - S on startup. Does not work in any fashion that i try.
I tried holding shift down. No safe mode. Just boots up to all the usernames. And it will login fine but still no admin privs.

When i boot up the system, i see a Grey screen, Then Grey screen with a apple, then a blue screen and then Usernames to login with.

So any help or tips to get to a single user mode would be appreciated greatly.

Also, i tried clearing the PRAM and NVRAM and will not do it. I only hear one sound and not the second

You really need to obtain an install DVD set for the machine. Call Apple customer service, give them the SN and model number, and ask for an original Leopard install set specific for your MBP. I'm not sure how much they'll charge but it shouldn't be too much. If the cost is too high, purchase the Snow Leopard upgrade at your local Apple store or Best Buy for $29.99.

With a new install DVD set you can wipe the hard drive and start over with a fresh install of OS X and apps.

Regards.

Thanks man!..I was wanting a new and bigger HDD anyhow.

But could there be a underlying issue of me not being able to boot to single user mode? It just goes to the user id to login to.