Sighting in at the bench should be a straightforward process, choose a calm morning for best results.
If the scope has just been fitted to the rifle, then you will need to bore sight first. If the scope has been sighted in before and just needs finer adjustment skip the bore sighting section.
Place a large target at 25m or 50m. Check the range is open so red light is on then set the rifle in a firm front and rear rest the less movement here the better, leave the bolt out. Sit at the bench and lower your head down level with the rear of the rifle and look through the barrel towards the target, you may have to move the rifle until you can see the target through the barrel, as best you can position the rifle so the target is dead centre. Now look through the scope, if the cross hairs are close to central you are good to go, otherwise carefully adjust your crosshairs until they are centre on the target be careful not to move the rifle during this process, once the adjustments have been made just double check again. If you are confident fire a shot and check placement. Bore sighting takes about 3 minutes and will get you on paper ready for the next step.
When the range is closed set up a target at 50m. Check the range is open so red light on and set your rifle in a firm front and rear rest to minimise any movement, take your normal shooting position from the bench and fire one shot aimed at the bullseye and check the point of impact, clear the action, after the shot be careful not to move the rifle so as to hold your point of aim, carefully adjust your cross hairs until they point directly at the bullet hole. Sometimes it helps to have a mate adjust the scope while you hold the rifle steady. Once the cross hairs align with the bullet hole aim again for the bullseye and take a second shot, this should have you on target already in only 2 shots, if not and you need some finer tuning repeat the process for finer adjustment and in 3 shots your done.