Breaking A Puerh Bing Cha ("Cake Puerh")

As with most "cake"Puerhs, the amount of tea used is rather difficult to measure since you will have to break off a part of the cake to make the tea and it is almost impossible to get exactly the amount you want. If you're someone who just kind of goes with the flow, then adjust steeping time and temperature according to the amount of tea. You can easily adapt and it will work just fine. However, most people want some kind of structure to follow, so will recommend three methods to break up the cake.
He Kai Shan "Green" Puerh - Bing Cha

Method one:  Break the cake apart by steaming 

Place the cake inside a clean muslin, food grade cloth bag. Be sure that the bag is of neutral color and doesn't have any aromatics. Gently steam until the tea begins to soften. Remove from steam and let it cool just a bit and gently break the cake apart. Let the broken leaves completely air dried before wrapping in cotton paper (again no aromatics from the paper) and keep the tea in an earthenware urn for safe keeping. This method help keeps the leaves more intact and doesn't produce so much broken powder. But some would hesitate to use this method, especially on older cakes, worrying that the steaming changes the flavor and if not dried completely, can cause mold to develop.

Method two: Puerh Knife
Bamboo Puerh Knife

Use a bamboo or wooden Puerh Knife. Gently insert the knife into the side of the cake, twist and life off the amount of tea you desire to use. This method produces more powder and broken leaves but is easy and no one has to worry about the steaming process changing the flavor or the potential to develop mold.

Method three: Break cake apart by hand

Gently break off a small piece by hand, starting from the edge of the cake and work your way in. The middle part of the cake is generally compressed harder and doesn't break off as easily as the thinner edges. But, as the cake ages, it becomes easier to break apart. Unfortunately, this method can cause more broken leaves and powders but it also the easiest way to get started.