Deleting Main User Account

So I'm looking to remove the main user account from any MB; I don't want to have to format everything I would just like to remove the account and the files while keeping everything else. Seeing as how the format and install take FOREVER! Is there anyway of doing this at all? We had tried a few things but the system files were all Read-Only and I had tried to chmod them so that I could read/write them but it didn't work. Any help would be awesome at this point. Ripping my hair out!

Create a new user account, give it admin privileges, log into the new account, head back to User Accounts and delete the first one.

Is there a way to do it where I can't create a user account? Basically we are getting a Mac returned and have old customer data that we want to remove and then make it like it's brand new

Reinstall OS X. When it gets to the setup assistant, quit it - press command Q, then power down the machine.

When new owner starts it up, the setup assistant will once again launch for them.

Don't know what you mean by forever, I've done it several times on mine and takes well under an hour.

As you've been advised, in order to do that you have to resort to erasing and reinstalling OS X. I don't know why you think it takes forever? Should only take around 20 minutes or more unless you run into difficulty.

Regards.