Although I booked a tour, can I change/adjust/extend it before / during the tour?

Yes you can adjust the tour before or during it provided that all members of your group agree. You may extend it as well for as many days as you want provided our schedule allows it and we agree on teh financial terms. You may reduce it provided you pay the days that stays in the tour plus a cancellation fee for the rest of the days amounting to 35 Euro.