"How do you get to the Olympic stadium?"
Yes, I believe it's the te form of yaru, which is another way of saying suru or 'to do' something. douyatte... basically translates to 'how do I...' , very common when asking for instructions.
I do not understand why オリンピック会場までどうやっていきますか is rejected. Reported on Oct. 31, 2017.