I found one on YouTube but it was in Japanese or something like that. It did however show how to disassemble. First you have to bend the fork back that the pump pivots on. just enough to remove the pump from the bracket. Then with the pump in your left hand grab the front cage with your right hand and twist it counterclockwise right at the point the pivot pins are at. It should turn about 20 degrees then the top cage will come off and give you access to the impellor.
skeeter