1998 Mercury 9.9/15HP 4-stroke outboards factory service manual, Page 34Get this manual
GENERAL INFORMATION
3Place block of wood between gear case and propeller to hold propeller and remove propeller nut
4Pull propeller straight off shaftIf propeller is seized to the shaft and cannot be removed, have the propeller removed by an authorized dealer
5Coat the propeller shaft with Quicksilver Anti-Corrosion Grease or 2-4-C Marine Lubricant with Teflon