Mercury Mariner 8/9.9HP 4-Stroke Factory Service Manual, Page 246Get this manual
5If the spiral spring is staying engaged to the drum, insert slotted screwdriver thru the hole in the drum and push down the spring Spiral Spring WARNING
Wear safety glasses and gloves for eye and hand protection when removing the spiral springAs the spiral spring uncoils it could cause injuryHold the starter housing facing downward and away from youInsert screwdriver into the shaft opening and push the spiral spring out