On web:
1. Open My profile (icon in the top right corner)
2. Open Settings
3. Click on Does your profile picture look good?
4. Click on Upload and upload your new photo
In apps:
1. From the Home Screen, tap on the Side Bar icon (top left corner)
2. Tap on "My Profile".
3. Click Edit profile
4. Tap on your photo
5. Take a new photo or choose it from your library