Congratulations on your inheritance.
That is one great old classic rifle.
And sorry for your loss.
Un-screw the big thumb screw on the left side and pull the rifle apart. Don't worry, nothing will fall out or get lost. That is the normal take-down feature in action!
Further disassembly is not needed for normal cleaning, but if you also take the stock off, you can get inside the rear of the trigger group.
That big long screw at the rear of the top tang that you see the end of on the bottom tang holds the stock on.
Take it out and slide the stock straight back and off.
Do not mess with the smaller screws on the bottom tang.
Thats springs and things!
If you want to take the bolt completely out, unscrew the side-plate screw at the front-left of the receiver.
Slide the plate foreword out of the dove-tail. Now you can slightly spring the op rod off of the bolt and with a little wiggling, remove the bolt from the rear.
rcmodel