In order to bulk upload all of your student photos to their appropriate profiles, create a zip file containing all of the student photos with the student's student number as the file name.
Once you have that file, log into the main administrator account for you district. Then, click on "Control Center"
From there, click "Uploads".
The default upload option when you click in will be profile pictures, so just drag and drop that zip file into the area surrounded by the dotted line, or click the center to open up a finder window and select the zip file that way.
Any successful uploads will show up in the list below the upload area. If you upload a new photo with the same student ID, the new photo will overwrite the old photo.
Make sure student IDs are correct! The only way to undo this upload will be to overwrite it with a new student photo.