A template for the extended abstract is currently made available on the abstract submission page. An MS Word template (dotx) as well as a LaTeX template (sty file + tex example file) can be downloaded. Both give identical results – use the one to your liking. It is advised though, to submit your paper as pdf, to ensure it appears as intended. You may be requested to provide the original doc or TeX files (including additional figure files).
Do not hesitate to contact me if any question or problem arises with the template.