If you don't know best to take it to a gunsmith.johnThe procedure for removing the bolt is . Safety catch off, dry fire, keep pressure on trigger, lift bolt and remove.
I found that the slightest involuntary movement of the trigger finger can prevent the bolt being released. My remedy is to point the rifle upwards, press the trigger with my thumb, maintain pressure with thumb, lift the bolt and remove.
The trigger unit is adjustable once the stock has been removed, however I would be inclined to ask a rifle-smith to do it.