On a Mac, if you want to remotely manage the client machine using ARD (Apple Remote Desktop), you can go to System Preferences > Sharing > Remote Management.
What if you want to configure a user to remotely manage the machine but you have only SSH access (or you want to run a script instead of going through the GUI)?
A command like this will help:
sudo /System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Resources/kickstart -configure -users username -access -on -privs -all -restart -agent
Just sub in the actual username for username.
More details at Apple Remote Desktop: Configuring remotely via command line (kickstart).