#6 Update Session Organiser instructions

[Robert Argent]

AZ:
Send a message to all session organisers that they
should remove reviewers if they have been incorrectly
assigned or altered as these reviewers continue to
receive messages and inevitably contact the session
organisers with questions about their ongoing role.
This causes much additional e-mail correspondence.

RA 060124:
This may be best done by adding an explicit instruction
re removing Reviewers