Under your login name select 'Update my details', then 'Delete Avatar', and hopefully it will change to 'Select new picture..' or similar
Thanks.Yes I think I clicked on update your details but their wasn't any option to update the pic. I'll try deleting it.
Dur.. scroll down deary.. 
.. I was wondering why I couldn't find the delete option.. You have to scroll below the table..
All done.. 
