Open local edit from remote terminal window.

remote_rmate.txt

ssh your_user_name_on_the_server@your_server_ip_address
Once you are logged in, you can write:

1 	sudo apt-get install ruby
2 	sudo gem install rmate

If the above commands were successful, you are again on your local machine. You will need to redo the next step every time you want to connect to your server, and locally edit a file. Now, we need to create a connection between our local machine and the server. If you are on Linux or OSX write:

ssh -i "<your pem file> -R 52698:localhost:52698 your_user_name_on_the_server_@your_server_ip_address

Then you can 'rmate <your file>' on the remote.