Mix flour, sugar, and coconut in a bowl
Cut the margarine into pieces and put it in the bowl with flour
Use your hands to gather the dough
Crumble the dough on a pan
Put the pan on a stove on medium heat and occasionally turn the crumble (just like when making scrambled eggs)
Remove the pan from the heat and pour the crumble onto a piece of baking paper
Allow the crumble to cool