Complex sentence: Stan elects to use his favor to bail Steve out of trouble, but when he is forced to frame someone for the armed robbery, he frames a boy from the private school with ALS (Lou Gehrig's Disease) whom he tagged as Jimmy Boombox.
Split into simpler sentences: Stan elects to use his favor to bail Steve out of trouble but is forced to frame someone for the armed robbery. Stan then frames a boy from the private school with ALS (Lou Gehrig's Disease) whom he tagged as Jimmy Boombox.