Changing engine oil

Hi guys, I drive a 2002 Tribute. I was just wondering how to change the engine oil. please help and give advice

hi, I just changed the engine oil, I used castrol edge sport. just wonder if Mobile 1 10w-30 is better than this. castrol is 5w-30.

I think it calls for 5w20 or 5w30 if i am not mistaken. I would stay with what mazda said to use.