You should not need a screwdriver. If this is a new rifle, it can potentially be seized or gunked up from hardened cosmoline. I've only ever seen this once.
1. Get some WD-40 or some brake cleaner(the stuff used to de-grease car brakes) that has a thin straw attachment.
2. Unload your rifle.
3. #### the action to the rear and lock the bolt using the bolt catch.
4. Orient the rifle so that the muzzle is on your left and the rear sight to the right of you.
5. Look down into the open chamber directly under the bolt. You should see a horizontal metal bridge. This is what prevents the firing pin from moving fully forward under momentum when the bolt is out of battery. You will note that this bridge extends downwards on the left and right side of the receiver. The metal in between the two extensions is the trigger housing.
6. Spray some WD-40 or some brake cleaner in this area wear the receiver mates with the trigger housing. If you pull the bolt all the way to the rear and hold it there, you will notice, on the right-rear side of this bridge, an additional grove that extends vertically down towards the trigger. It's located on the bridge and is directly under the extractor when the bolt is locked. Apply more WD-40/Brake cleaner here.
7. Go watch some TV and leave the rifle alone. After about 30 mins or so try to disassemble the trigger guard as seen in the video.
8. IF THIS STILL DOES NOT WORK, TAKE THE GUN TO A SMITH/DEALER FOR INSPECTION.
IF this is successful, ensure that you thoroughly clean out the rifle. Dont use wd-40 to clean.