Yes, a flat head would work if you don't have any torx handy.
Taking it slowly after returning stuffed from a full morning out (0530 - 1300 and 300+km) on a BMW Club breakfast run, it took me about 3 hours, including a coffee break and medical attention to self inflicted cuts to my left hand.
And yes, sounds daunting but is quite easy with the video help and photos you have posted.