For personal reasons or if you no longer want to use your Facebook Messenger account, you can delete it from a computer. However, before you can exit the application, you must deactivate your primary Facebook account.
Steps
Part 1 of 2: Disable Facebook

Step 1. Open this page in your web browser
If you are not yet signed in to your Facebook account, sign in first.

Step 2. Click the down arrow
This button is located at the top right of Facebook and opens a menu.

Step 3. Select Settings
This option is at the bottom of the menu.

Step 4. Choose Account Management
Account management is located at the bottom in the right panel.

Step 5. Click Deactivate Your Account
This option is at the bottom of the gray section DISACTIVATE your account in the right side panel.

Step 6. Enter your password
Then click on Continue.

Step 7. Indicate your reason for leaving
If the reason that prompts you to close your account does not appear in the list, choose Other then type something in the field.

Step 8. Choose whether or not to receive messages from Facebook
Facebook will continue to send you emails when your friends tag you in photos, add you to groups, or invite you to events. If you no longer want to receive these emails, check the box Stop receiving messages from Facebook.

Step 9. Click Disable
A confirmation message will appear on the screen.

Step 10. Select Deactivate Now
Your Facebook account is now deactivated.
- If you've never used Facebook Messenger on a phone or tablet, your account is now deleted.
- If you are using Facebook Messenger on a phone or tablet, skip to the next method to deactivate your account.
Part 2 of 2: Disable Messenger on Mobile

Step 1. Open Facebook Messenger on your Android, iPhone or iPad
The app icon looks like a blue chat icon with a white lightning bolt inside. Usually, it is found on the Home screen or in the application drawer (on an Android).

Step 2. Tap your profile picture
Your profile picture can be found at the top right of Messenger.

Step 3. Look for the Privacy and Terms option
This option is at the bottom of the menu.

Step 4. Select Disable Messenger
Disable Messenger is at the bottom of the list.

Step 5. Enter your password
Then, tap Continue.

Step 6. Tap Disable
You will be logged out and your account will be deactivated.