Hittade lösningen själv. Men tack iaf.
1. Boot into single user mode (press Command-S at power on)
2. Type fsck -fy
3. Type mount -uw /
4. Type launchctl load /System/Library/LaunchDaemons/com.apple.DirectoryServices.plist
5. Type dscl . -passwd /Users/username password, replacing username with the targeted user and password with the desired password.
6. Reboot