Workshops in organ improvisation can be arranged for children, young people and students. An example of a workshop for diverse age group is "Pilgrim i orgelsko" which happened in Trondheim Cathedral in 2016.
At the final concert, all 10 pupils (age 8 to 19) performed two pieces of repertoire each, and participated in group improvisations.
I have given workshops in organ improvisation for students on bachelor level in Norway and internationally, for example at the Music academies in Copenhagen, Gothenburg, Oslo and Belgrade. Typically a workshop of 1-4 days with student groups of max 5 is combined with a lecture and a solo concert by myself, and/or a concert by students.
Read the report from workshop in Belgrade, Oct 11-15 2010 (w/sound examples)