If the option is enabled in the details of the course/multipack, it is possible to renew them from the E-Commerce: in the Home Page click on Shopping -> Your Shopping

In the list of purchased subscriptions, click on Renew

The system will renew the course with the same activity, day of the week, time and skills required for the course. 

Example: a tennis course on Thursdays at 7pm cannot be renewed via the E-Commerce if the client wants to attend on Mondays rather than Thursdays, because the system would keep the same characteristics of the current course.