• Warm the milk
• Mix it with the curd properly and keep it in warm place for 6-8 hours so that it forms sweet curd
• Take a thin cotton cloth and put the curd in it and hang it so that water is drained completely
• After 8-10 hours the curd will not have remains of water and you can untie the cloth and take the material(we call it chakka) into a vessel
• Mix it with sugar and keep for atleast two hours
• Mix the mango pulp with it and strain through Puran Yantra

Notes
The quantity for sugar need to be adjusted according to the sweetness of mango pulp. The pulp that I bought wasn't too sweet. But if pulp is already sweetened then accordingly decrease the sugar quantity.
Keeping the sugar mixed with chakka for couple of hours lets it mix properly. Otherwide the curd might get sour and separate out from sugar.