i just started learning 8051 2 months ago as part of my subject in school.

If your teacher has set you this assignment, then he probably expects you to read the data sheet and work out for yourself how to do this - after all, that's what we all have to do when we start on a new chip. Once mastered, it is an invluable skill which will serve you well for years to come.

SO, go and read that datasheet and then, if there's something specific you don't follow, ask you teacher.
Maybe ask here too!