Mix all the ingredients such that no lumps are formed. Then microwave it for 15 sec for about 7 -8 intervals. You can also mix it in tava and heat in gas. After each interval take the mixture out and stir well. After 7 or 8 intervals the mixture becomes solid  and it wont stick to the vessel. At this point take it out and knead it well by applying lotion in hands for about 10 min. Then wrap it in a polythene cover and refrigerate it in an air tight container for 24 hours.   I have attached the link of the video tutorial at the end of this post which I followed.