Removing Retaining Rings

[ehaataja]

I just bought a 1969 Johnson 55hp, model number 55ESL69C. I need to get the gearcase apart, but there's 2 very stubborn retaining rings holding in the shifting mechanism. Does anybody know if there's a special tool available for removing these rings?

EDIT: Nevermind. I got an 11 inch neednose pliers and ground the ends to be hook shapes, like this ---> ( ). The rings came right out.