Take a pot or a pan and place it on a burner set to high. You need a temperature of approximately 260°C to roast coffee.
When the pan has heated sufficiently, pour the beans in and begin shaking but be careful not to remove the pan from the heat and do not let the beans come to rest on the pan surface. If you do, they will burn. To keep the heat and beans in the pan, you may wish to use a lid. As you shake the beans, you will begin to notice the beans changing colour, from an olive green to a yellow-green hue. You will need a lot of wrist strength to keep the beans moving from 6-9 minutes, and perhaps much longer (depending on the roast style you prefer). Another option is to use a whisk - but ensure you are turning the beans rather than just shuffling them.
After around 6-9 minutes, you will hear the first crack. Once this crackling stops, the beans should have turned a light, golden brown.
From hereon you will need to keep an eye on the colour of the beans to get the roast you are after.