General locked out of my I Mac

[NickBangZ 0]

so I bought an I Mac from craigslist it had an admin password on it but not a log in pw 

Iended up figuring out the password I changed the pw to one I use on my laptop..........

or so I thought.

I wake up the next morning and password won't work and not only did I change it I set it so there is 

a login password I can't even get in it now how do I log into this thing? 

[Amuyea 88.2k]

From Internet:

"To get started, you will need to restart your computer. Press the Command and Rkeys at the same time when the grey screen appears and hold them until you see the Apple logo. A small loading bar will appear under the logo. Sit tight as your system boots into Recovery Mode.

Click the Utilities tab in the top menu bar, select Terminal, type resetpasswordand press Enter. Close out the Terminal window and behind it you will find the Reset Password utility. All you have to do now is select the user account you want to reset, enter a new password or leave it blank and click Save. Then just simply restart the computer from the Apple menu and login with your new password. It's as easy as that."