I have multiple Atlas O-gauge switches, while I really like the appearance of the track, if I had to do it all over again, I would use Ross switches. I am attaching the Manual, which I just scanned (the Atlas website is not that great, no manuals for the track (I just looked). Below is the page with the exploded view of the switch machine. The only tricky part is the spring, I use tweezers to attach the spring. Hope this helps.
Also, If you give up and need to replace the switch machine, Trainworld, a Forum Sponsor, have them in stock, for a reasonable $19.99.
https://www.trainworld.com/atl...hine-atlas-6099.html
Best, Dave