First obviously you must have your iPhone plugged into your computer through the USB cable. Then proceed with the following steps:
Step 1: Click on Hulkshare Link
Step 2: Click "Download File" and make a specific folder in which you would like to save your ringtones.
Step 3: With the Ringtone Folder open click, hold, and drag the desired ringtone into your "Ringtones Folder" in your iTunes library.
tep 4: In iTunes, under devices select your phone. Then select ringtones. Then hit sync.
Step 5: Enjoy.