Whole assembling process is showed on the video in the introduction so if you want to follow it, just do it. If you prefer reading my bad english explonation on how to make it here it is.

You can begin with puting M10 screw in the hole that we had drilled moment before. Tighten it with a nut then put a washer on it, your fidget spinner without a caps (this little buttons that you hold spinner with) and again washer and nut. Arm that will spin our spinner is made out of 2 servos with two 3D printed elements. You have to fix bigger element to the servo on the bottom wih M2 screw and then to the top of it second servo with zip tie. To the servo on the top we also have to fix a smaller 3D print with M2 screw. Than this arm has to be fixed to the base with a zip tie. And that's all. Hope you understand if not check out video and photos or ask in the comments.