Unwrapping UV of a crab shape in blender

Hi everyone
Sorry if I’m stupid for making another thread, I couldn’t see a megathread for modelling questions.
Anyway, I am currently making a hat for the spy (for team fortress 2) which appears as a crab sitting on top of his head. The model is complete…but I have no clue on how to unwrap it, mainly because of lack of experience and also because it’s a pretty weird shape.
Could someone please help me?
A link to my file is here: http://www.mediafire.com/?l9d46cmhg22735b
All help is appreciated

There is a tutorial here: https://developer.valvesoftware.com/wiki/Blender_Modelling_Walkthrough
I’m no good at it, but I would mark seams up the sides of the legs and half way around all the rounded parts.