[hiccup]

Tiara has used different couplers over the years. Most typical is a tapered fit between the coupler and the shaft with a large nut holding them together. Obviously you have to remove the coupler from the transmission to gain access to the nut. Assuming the coupler has not been removed in many years, this is usually a really fun project (!). Getting the nut off will probably not be too hard using a large breaker bar and large chain wrench to hold the coupler. Getting the coupler off the taper, I have had luck with a low-profile puller and carefully applied heat to the coupler. With gas engines you have to be extra cautious with the heat, perhaps using an induction heater like the mini ductor rather than an open flame.

An email to Tiara customer service with your HIN might get you a drawing of your shaft/coupler which would tell you how it's held on and the size of the socket you will need for the nut and whether or not you will need to source (or make) a thin-walled socket. I am probably making it sound worse than it is--it's totally doable, good luck!