To do any topside trick you must be pretty experienced. What you have to do is just lean over the opposite way of the utensil. There is really not much to say about any of the topside tricks and how to describe them except that you must lean over the opposite way of the utensil. Also when you are just starting to learn any topside trick it is easiest on a rail of some sort (even the low part of a bike rack) and from there you can get the correct balance and take it to a planter, ledge, handrail, etc. The key to topside tricks is just a lot of practice, balance and if you lean out you will get topside (it's essential on curbs, ledges, etc.)