Fairly self explanatory. They take 2,387 vintage figures, put them in a tank and dissolve them in acetone.
https://www.youtube.com/watch?v=bf2tBFfMLMkThey did something similar (albeit on a much smaller scale) in 2015 to "celebrate" the return of Star Wars.
https://www.youtube.com/watch?v=H1pn4bTAQWA