I applied to school a (preferred school) and school b (fall back), and was accepted to both. Both also offered assistantships, but school b's offer was more than twice school a's offer. Unhappily, I accepted school b's offer strictly out of financial need.
April 15 passed...fast forward to mid-July. School A came back with a fellowship offer. This is not a difficult decision; however, I'm required to obtain a written release from my school b commitment before I can accept the fellowship from school a.
I have not done anything unethical IMO, but I'm worried about school b busting my chops and so on. What's the best way to go about getting a release from school b and what kind of scenarios can I expect?