The workshop is held at the campus of DESY Hamburg. You can enter the site and pass the porter's lodge as a visitor without any further ado.
How to reach the DESY campus is described in detail under
http://www.desy.de/about_desy/getting_there/hamburg/index_eng.html
The meeting will take place in the DESY main building conference seminar room SR4b in building 1.
A ground plan of the campus showing this building can be found at
http://www.desy.de/content/desymaps/gelaendeplan-eng-hh.pdf
If you are not sure where to go once on the campus, don't hesitate to ask the porters!
