Can we just chop our Micro Sim up and put in our new IPhone 5?

So a lot of us have Iphones with a micro sim so can we just chop it up and put in our Iphone 5 when we get it? I live in Vietnam so rely on grey imports as official models can take a year to arrive, which will mean the carriers will be slow to adopt the new standard for sure? Will there be new cutting tools or can we trim by hand?