I actually cannot recall my offical answer on this as I've seen this question in the past.
I believe (depending on if it is actually hash, and not just kief pressed) that you can in fact eat it without heating it. The purpose of heating it is to get it to extract. If you really want to extract it back down into some sort of liquid, you need a fatty substance. Think oil. So, instead of making oil with cannabis plant, you can make it with the hash you have, by the same methods of cooking with cannabis (see directory for instruction on how to do this)...
however... I believe since it is already an extract, it should be able to be activated simply by consuming orally already. Again, don't take my word as law, but according to the science I know of cannabis, I don't see why this would not work as it is already an extract. It may need to bind further onto a fatty lipid to become MORE bioavailable through oral consumption, though.
I'm sure someone else can weigh in on this