Stuck on 42066 Air Race Jet model B
Nice job finishing Model "A"! 

As for Model "B", known as "Private Jet", follow this link and head on over to Youtuber THINK LOUDER's speed build of this model.




First, Mute the video.
Second, Pause the video.
Third, Open the setting for video playback, which is the "Gear" icon
in the bottom right hand corner of the video, to slow down the speed to "0.25". 
Forth, Play the video and skip to minute 1:47 into the video.
Fifth, and finally, Watch how this guy builds up until minute 2:04 into the video, which is where you are stuck, page 7, instruction 8.




Good luck! You can do it Bro!