Mobile App: Changing your name, phone number, avatar
You can update your personal details (name and phone number) and an avatar photo from the mobile app.
Covered here:
Changing your name & phone number
If you need to change personal details, tap your name at the top, then Edit profile. Change the details (name and/or phone number), then save your changes.
Changing your avatar photo
To upload a photo or change the current one, tap your name at the top, then tap the photo itself. You will then be able to upload a new one from your device. You can crop it, leaving only the area you want. Your new avatar will start displaying as soon as it is uploaded.