Earlier today, the Grand Duke's brother Prince Guillaume visited the European School of Luxembourg to promote the Mérite Jeunesse, an award similar to the The Duke of Edinburgh's Award. A detailed outline how to get the different awards in gold, silver or bronze can be found on the homepage of the Luxembourgish private school Sainte-Anne, originally in German but dutifully set on English by me.
Apparently, Grand Duke Jean is the patron of the Mérite Jeunesse while Prince Guillaume works as the president of the board. In this capacity he promoted the Award at the European School to find new mentors to help the numerous young people between the age of 14 and 25 to achieve their goals, as well as new schools to participate in the program that is run without any competition between its participants.
Sources: Mérite Jeunesse, 352 Lux Mag, picture taken from mywort.lu