go to your profile page, click on photos
on next page click on upload
a popup will appear, here you will choose an album to upload photo to, select xxxxx photo, xxxxx you will replace with your profile name. search for this folder and click on it
after selecting album another window will appear, click on continue.
on the next page you will choose which uploader to use to upload your photo, you also have an option to take a photo, anyways, click on select files then choose from your devise the photo to upload, once you select photo it will appear like in photo below. click on submit and your done.
if you want to change your profile photo simply go to your profile photos album and select image to use