STEP 1: Download the forge Installer for the version of forge you would like.
All installers can be found here: files.minecraftforge.net
STEP 2: Create a folder called "Server" on your desktop.
STEP 3: Run the installer you downloaded and select "Install Server". Press the 3 dots at the bottom of the installer and find the folder you created on your desktop. Then, select open.
STEP 4: Press "Ok" and let the installer run. This will then gather all the necessary files for your server and place them in the folder you just created.
STEP 5: Using SFTP, upload all the files that were just created on to your server.
You can learn how to use SFTP here: https://lowhosting.org/clientarea/index.php?rp=/knowledgebase/10/How-to-manage-files-using-SFTP.html
STEP 6: Rename the forge jar file to server.jar or follow our tutorial on how to install custom jars.
Installing Jars can be found here: https://lowhosting.org/clientarea/index.php?rp=/knowledgebase/8/Installing-a-custom-server-jar-file.html
STEP 7: Restart your server.
All done! Enjoy your fresh new modded server.