Hello Peer,

Today, this means to edit the core files of iCagenda (not recommended).

In the same time, many things will change in 3.6.0 (almost all the frontend files and logic!)
And even if participants list won't change in 3.6.0, the code was moved to the Library. And later (in one of the 3.6.X update) i will full refactory this code, to allow more flexibility, as well as displaying more options with infos (and to allow to show custom fields there too!).

So, i would say: thanks for your patience, many things and possibilities are in process or planned for a near future!

Best Regards,
Cyril