forgot password for admin how can i reset

Reset Admin Password

Restart in Recovery Mode (command-r). From the Utilities menu in the Mac OS X Utilities menu, choose Terminal. At the prompt enter “resetpassword” (without the quotes) and press Return. A Reset Password window will pop up. Select your startup volume in the top of the window and then, from the pop-up menu select a user account.

In the fields below enter and confirm your new password then click on Save. Now choose Restart from the Apple menu. Your Mac should now use the new password you’ve created.