1. Ensuring all is up to date- Ensure you have Mac OS X 10.7 or higher and OS X Recovery. If you have Lion or later, you’re good to go on both of these.
2. System Preferences- You will need to get into System Preferences to get started. Click the Apple icon located at the top left of the screen. From the drop down menu, click System Preferences and then click on Security and Privacy.
3. Security and privacy options- The Security and Privacy window will open up. From this menu, click on File Vault. In the File Vault options, click on Turn on File Vault.
4. User account access- Now, select the user accounts that will have access to the encrypted files and then click Continue.
5. Recovery key- You will be given a recovery key that you will have to enter so you can access the encrypted volume if you happen to forget your account password. Take note of this recovery key. Click Continue, then select whether you want Apple to store the recovery key or not.