Without damaging the pump housing
An easy way to remove your old engine impeller after removing the cover plate is to spray it with PTFE lubricant. Then turn the engine over on the battery a few times – making sure that the engine WON’T start by pulling out the engine stop control. Now grab hold of an impeller fin with a pair of pliers and it should slide off the spline with little effort.
No need to use a screwdriver and thereby risk damaging the pump sealing flange.
Thanks to PBO reader Peter Baylis for his tip. Send yours in – email firstname.lastname@example.org