I have done this many times : go through
T2 connecting point , go through security
check..take the elevator to your right and
go up to the departure level and go into
the FC lounge...And reverse the process when
you are ready to leave the airport..The
security people will look at your boarding
pass and let you go through the back of the
screening machine : and you'll be back to
where you start off : at the arrival level.
And off you leave the airport through
Immigration , etc.
Hope this helps