5 EC can be obtained for participation in a full Summer/Winter School, e.i. attending two courses in week 1 and two courses in week 2 (3 EC for attending the courses; 2 EC for the paper).
Please note that, in the Winter school, there are two different kinds of courses:
In the Winter school, there are courses specially designed for first-year research master students. These RM1 courses give 2,5 EC each and require more preperation than the regular courses. Students are required to follow two of these courses. There are also regular courses, these courses give 0,75 EC each. Second year research master students are required to follow four of these courses (4× 0,75 = 3) and write a paper of 10 pages as a sequel to one of these courses. The exact requirements you need to negociate with the LOT instructor (note that the lecturer should be affiliated with a Dutch university).
You will need to actively participate in the LOT courses; read the materials and attend the lectures. There are no exams.