Breaking the block.

Ice is made of the same material as water but it is not water. It does not flow. The difficulty arises when we expect ice to behave like water.

We can either break it with force or sit long enough with it for it to melt. But if we do not change the conditions that turned water to ice, we can't expect it to turn back into water.

If it was easy to break the block, there wouldn't be a block to begin with.

PS. Also, if we apply too much force or heat it too much, everything can turn into vapour too.