This can be done from any 0365 application as well.
- Open Microsoft Teams
- In the upper-right, select the circle with your existing picture or your initials
- Select your image again. A little camera icon will appear over the photo if you hover your cursor over it.
- Select Remove picture to delete the existing image and just have your initials show
- Select upload picture to upload from your device and replace the existing picture or add an initial picture
- Navigate to the location of the picture on your device and select it.