Got my answers from " The wiper man".
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Would you mind sharing for those with the same issue in the future?

@tiny From what I have been told the link arms and pivot assemblies are installed by feeding the arms and pivots thru the cowl from the outside and then connecting to the pins on the wiper motor.  The arms are retained on the pins with clips connected by a spring. Lubing the rubber inserts in the link arm helps-I used WD-40 when bench testing and they slipped right on. Once I get both splined "drivers" which need to be pressed on the shafts I will install all parts and hopefully move on to the next phase of assembling the dash controls, heater and wiring. Had I known how hard it would be to locate the "driving cones" i would have been more careful in removing them as I destroyed both getting them off. Also noted under the splined driver which is recessed on the inner surface are wavy washers to retain tension on the arm. It is best to remove the "driver cone" by grinding the swaged shaft end on the link arm. Then place a spacer over the shaft and under the "driver"and press the shaft out. I used my drill press as an arbor press and for a spacer I removed the pin,ball, and spring from a pin style grease fitting. After drilling the end of the fitting (1/4") it fit perfectly over the shaft and under the "driver".