Yes the rod moves slightly but barely it can be push/ pulled slightly dose not turn any thaughts?

In reply to your question about when did it last move we have no idea. as we baught the engine all ready out of the car and was very very dirty as for the stuck tube with spring and ball bearing which is coverd by the differential when looking at the twisty gear change rod with hole to change gear that as well as the tube are stuck in place.
How do we remove that tube we have removed the ball & spring all we need to remove is the tube. then get the gear rod to get out of gear in order to lock two gears into place, then remove the nuts holding the gears in place. Any ideas. 

Any and all suggestions welcome.

WHen was the last time it moved on it's own? Has it been in a flood or anything where water may have filled the gearbox? As far as releasing the pressure on the slave cylinder push rod, all you need to do is take the bolts out of the slave cylinder where it mounts to the transmission.

Does the shaft move at all? Or is it moving little with internal mechanical stops. Is this out of the car? If its out try putting them in and  turning the output shafts while at the same time trying to shift. Or with th plugs out turn the engine crank back and forth while trying to shift

We have tryed pushing pulling twisting the pin to disengage the gear but it seemed to be stuck in reverse gear, also you know the with holding the key for the gears that slave is stuck as well any ideas how to in stick that? We have tried to pull it out we have tried using lubricant and left over knight but still stuck. ?? Any ideas?

push, pull, and or rotate the selector shaft to find neutral. Slip a small screwdriver through the roll pin hole to work it.

How do you un stick a rod change gear selector shaft?, Due to we are stripping an 850 engine and it won't disconnect /un select gear.