Hi, it sounds like the pin that you are referring to is the pivot pin at the front end of the lower lift arm. If this is the one you are lucky to be able to turn it. The pin is(should) be fitted into a taper in the axle housing. On the inside there is a nyloc nut. The only way to remove the pin is to remove the axle housing.
If the pin to be removed is on the left side you will need to be VERY careful when you remove the axle awat from the centre housing. The reason for this is that the differential may come out with the axle housing. If you use a means of lifting you will need to take this into account. Alternatively once the axle housing is about two inches out it is possible to place a rope or strap across the differential and tie both ends. This will keep the diff in place. Remember that all parts are very heavy. Simply remove the nut and pin. Fit a new pin and tighten. Make sure that the pin is tight in the taper and that the nut does not 'bottom' on the pin itself. If the old pin was loose there may be elongation in the taper.
Let us know how you get on.
DavidP, South Wales