ok pry that centre out
normally you would flex the case but a pry bar will ping it out along with its beraimgs and shims
stand center it in a vice with the bolt heads upwards
and undo the bolts that hold both parts of the centre together (not the bolts for the ring gear)
take off the top half bits will fall out
don't loose any little dowels that old the cross pin in place
pull off the spider gears and any cupped shim washers
Job done
Dave