To split the cases you will need a specialist tool. They cost around $ 60 upwards. Rocky Mountaain make one as the link below.
However, you can make one quite easily with slotted UNISTRUT and M6 and M8 threaded rod and nuts. If you have non-slotted UNISTRUT, you will need to drill some holes top match.
UNISTRUT is very cheap or if you know someone, they may give you a short length. The whole tool cost me about $5.
If you message me, I will email a picture.
I will try and post a picture and instructions in due course.
My crank popped out in no time. The flywheel side is threaded M6 and the clutch side has a hole in which an M8 bolt fits easily.
To push the cases from the crank:
1. screw in a M6 rod into two of the bolt holes in the crankcase and lock down with a washer and nut.
2. screw in an m6 (for flywheel side) threaded rod or slide in a m8 (for clutch side) threaded rod into the centre of the crank.
3. put a nut on each rod about 6 inches higher than the crankcase.
4. put the unistrut on the three rods and
http://www.rockymountainatv.com/productDetail.do?navType=type&webTypeId=140&navTitle=Tools%2FShop&webCatId=22&prodFamilyId=17167