how do I get check oil light off the instument panel off.

At the repair shop when they do an oil change or any other services they use obd reader to clear all the service codes (i.e Change oil light, ect.). If you know anybody who has an obd I or II reader depending on year i think yours is an obd II becuase i have the same year truck that has one of these you could clear it yourself. If not alot of service shops will do it for free you just have to look around. Basically you just have to clear or reset the code from the trucks computer so it can start the mileage over again so the next time you have to change your oil it will tell you.