if you can manage to get the drivers floor out better working from top this weather, there is a cover on the end of the front output housing that covers the shafts, this can be undone with 3 small bolts and pulled forward a bit you will see the end of the 4wd shaft, when the yellow know is pressed it lifts the pin out of the locating hole in shaft and shaft should move forward under spring pressure, if it dosent it could be siezed as fenby says , clean the ends and try puilling it out with pliers, if it comes out the transfer lever will move it back into place can be locked with the 4wd pin