Click the Apple logo in the upper left corner of the menu bar, then System Preferences, then Sharing in the System Preferences window. This will bring up the Sharing window. You can rename your computer, alter its name for local area network (LAN) access, and so on from here.
From the drop-down menu, select File Sharing, Remote Login, and Remote Management. On the target Mac, this allows the three sharing services. You may also define the service's permissions for the users as you check each box in the right section.
From the menu bar, select Go, then Connect to Server. The Connect to Server dialogue box appears. You can use this interface to connect to remote computers, save their addresses for later use, or delete any existing remote connection entries.
Click Browse, then double-click the name of the destination computer (in this case, Peter's Mac) in the Network box, then click Connect. Click Connect from the top bar, then input the credentials of a user account (usually an admin account) on the target machine (peter in this case), and click Connect.