Retrieve (Recover) Deleted Messages From Facebook : Acid

Complete Tutorial to retrieve deleted messages from Facebook ID [Acid's Method]

Many users have requested for the Facebook Tips and Tricks category on our blog. So, here is the first tutorial. For more tutorials check our Tutorials section. I'll be updating it regularly.
Now, lets come to the point. This tutorials is written assuming that you know a little or nothing about the social networking site. Therefore, it is completely detailed including screenshots. To start the process follow steps in the sequence undermentioned. The method I've used for this purpose is Acid's Method. You can search about it on facebook for further.

STEP 1 : Navigate To The Settings Page

Click the cog-shaped icon on the top bar after logging into your Facebook account, and select "Settings" from the drop down menu. You'll be redirected to the main settings page.

STEP 2 : Move To GENERAL

After you have reached the settings page, Select General. Most of the users will have the "General Settings" page opened by default. If it is so, then you can skip this step.

STEP 3 : Click On Download

In the General settings page, move to the bottom and click on "Download a copy of your Facebook data."

STEP 4: Click & Wait

Click on "Start my archive" on the next page. They'll ask you to wait till the archive is ready. It takes about 3 minutes on average. In the mean time, log In to your Email ID. The archive may be sent to your Email, or it may be downloaded directly from Notifications. (If you don't have email enabled, they will send you a notification. Otherwise, they will send you a link to your archive in your Email Inbox). So open your Email account and wait.

STEP 5 : Click The Link in Email

After some time, you'll receive an email which reads that "Your Archive is ready to download". See the screenshot below.

STEP 6 : Click On Download

You'll be redirected to the Facebook page where you can download your Archive. Click on the green button that reads "Download".

STEP 7 : Enter Your Password

For security, Facebook will ask you to enter your password before you can download your archive. Enter your password and click on Submit.

STEP 8 : Final Step

You've reached the final stage now. After you click submit, your download will start which will be a zip file. Extract that zip file in some safe location. Now go to the location where you extracted the file and open the index.html file. When you've opened the file, navigate to the messages by clicking "Messages" from the side menu. On the messages page, you'll have all your messages including those that have been accidentally deleted.

NOTE: Your archive contains all your sensitive data and messages including photos. Adopt strict measures for your privacy such as password protecting the archive.
You'll only be able to retrieve the messages if you haven't started conversation with the person again. For example if I had a conversation with "John" that was accidentally deleted. If I follow the above process, I can retrieve the conversation. But If I have started another conversation before following above steps, I'll not be able to recover deleted messages.
This article was written under "Facebook Messages Hacking" only for informative purposes or to help you in recovery process.