Need help from England. ( or Canada )

First clean up the engine front, take of pully from crank then look very carefully for some covered stud holes the paint useally hides them if they are there remove the plug and insert a stud and the housing pushes off.

If that fails use a strap or chain wrench and apply pressure both clockwise and anti clock wise DON'T JAR just steady force this may take time but persevere. There is at least one dowel fitted and it is a tight fit!!

Lastly on some commercial versions there may be a groove if so use a drift knocked in from the side there usally is another groove opposite so work each groove in turn to fetch it off evenly

hope this helps and good luck with your project