I applied for graduate admission in Canadian universities for fall entry. One of the graduate programs offered me admission in February and furthermore offered me a prestigious scholarship to motivate me to accept the offer of admission. I accepted the offer of admission and the offer of scholarship in February. A few days back (early May), I received an offer of admission from another more lucrative graduate program. I would like to accept the new offer and rescind the old offer because the new graduate program has research groups more in line with my own research interests. However, I am uncertain as to how I should reply to the admissions chair of the old graduate program that I want to rescind their offer of admission. It's been nearly three months since I accepted the first offer. What would be the polite way to rescind the offer of admission? P.S. A couple of professors from the old graduate program also expressed their interest in supervising me (in February). I told them that I would get back to them soon after but it's been three months and I still haven't replied back to them. Should I also send them an email stating that I rescind the offer of admission?