what volume would a gas occupy, if you had a 37.L cyliner that was 45 atm and temperature of 18C was released to the atmosphere (P=760.mm Hg) which had a temperature of 37C?

Can you show me how to set this up?

Your sentence structure makes the problem difficult to understand. I think you are asking for the volume of a 37L cylinder originally at 45 atm and 18 C if it were released to the atmosphere with 1 atm P and 37 C. If I have interpreted the problem correctly, use

(P1V1/T1) = (P2V2/T2)
Don't forget T must be converted to kelvin.