以下是原文:
Change an Admin Password in Mac OS X Single User Mode
This is a multistep process but it’s easy to follow:
First you need to enter Single User Mode. Reboot the Mac and hold down Command+S at boot to enter into the command line.
You’ll see a note where Mac OS X tells you that you need to run two commands in order to make filesystem changes, this is necessary so let’s handle that first
The first command checks the Mac OS X filesystem for errors and fixes them, it can take a few minutes to run:
fsck -fy
The next command mounts the root Mac OS X drive as writable, allowing you to make changes to the filesystem:
mount -uw /
After the filesystem is mounted, you can reset any users password using the following command:
passwd username
You’ll need to enter the new password twice to reset and confirm the changes