Hi DK
It really depends on the piece of Sunstone that you have, do you know where it is from? Does it have silver or gold speckles?
As a general rule I would quickly cleanse the piece under cold running water, ideally a freshwater stream, waterfaall or brook, but your cold tap will do fine

Shake it dry and then use a natural fibre cloth to finish the job, cotton, or silk etc.
I do not believe in programming, for me the crystals know far better what they are here for and we will be drawn to the right one at the right time. Now is the time for you to work with Sunstone
Hold the stone in your dominant hand first, ( usually right if right handed, or left if left handed ) Find a quiet place and seat yourself comfortably, use music or incense or candles and relax. Look at your stone carefully, look at it in detail, turn it over and over, feel it in your hand under your thumb, feel the cracks or dents or how smooth it is. Get to know the piece. Then do the same in the other hand, take your time and see how you feel, what emotions and thoughts come to you. How does this stone make you feel? Then perhaps place it over your heart chakra, or your crown or third eye, whereever you are drawn to. see how it feels, how do your thoughts change? Then relax and calm your breathing and visualise a trip inside the stone, what does it look like? What does it smell like, what can you see? You may find yourself in a red room or a golden cave or somewhere else totally. Ask yourself what the stone is best at, what does it want you to know, why is it here.
Start with this and see how you get on, the stone will tell you the rest.......