Log in on the collaborators app.
Click on 'Home' in the upper left corner of the main menu.
Select 'My profile'. You arrive on the following screen.
Click on 'Change Profile picture' to take a picture or choose a picture from your device library.
Click on 'Log in data' to modify your log in data.
Click on 'Personal data' to modify your personal data.
Click on 'My profile' to modify your profile.
Do not forget to click on 'Update personal data' if you have modified something.