First thing, you need to have the correct executable in your $PATH:
sudo mv /usr/sbin/apachectl /usr/sbin/apachectl-mac
sudo ln -s /Applications/MAMP/Library/bin/apachectl /usr/sbin/apachectl
Next you need to give yourself access to call `sudo apachectl restart` without having to enter a password:
sudo visudo
Learn how [vi text editor](http://www.howtogeek.com/102468/a-beginners-guide-to-editing-text-files-...) works, and In the ensuing file, enter the following line, where `my_mac_user_name` is your username on the command line (find it by typeing `whoami`):
my_mac_user_name ALL=(root) NOPASSWD: /Applications/MAMP/Library/bin/apachectl
Now you can restart Apache from the command line by typing:
sudo apachectl restart