Go to the XLink homepage. Login with your current Xtag / password on the right side.

Select 'Edit My Profile'.

Scroll down to the bottom and you will see

“Avatar / Display Photo (50 x 50 pixels only):”

with a box beside it .. fill out the path to your image in that box.

you have to find a place to host your picture. also make sure your picture is 50×50 ..

Ignore this “Got nowhere to host your avatar? Try 3xodus's free avatar hosting!” as it doesn't work at this time.