Hi, Steelbuster,
Boy, are you into oldies. You might not want to tackle the disassembly job after reading this, but here goes. A vise with padded jaws will help but you can get by without it.
To disassemble the rifle into two main parts, grip the buttstock and insert the point of a bullet (.30-'06 ball works fine) into the hole just behind the trigger guard and push upward, while pulling forward on the barrel. The trigger group and stock will come away from the receiver. (If this reminds anyone of the SKS takedown, Simonov was a copycat.)
Behind the front sight there is a little dovetailed cover plate. Tap it out left to right, and remove the screw underneath it. Now with a block of wood, tap the gas block (the part with the front sight on it) forward until it comes off, along with the gas cylinder. (If this reminds anyone of the original M1 rifle gas trap system, Garand was a copycat.) The foreend and foreend tube can now be removed.
The gas piston is now exposed. Unscrew the piston (it has a screwdriver slot in the head). Make sure the spring is kept captive; it can whip when released and injure an eye. I have seen one that had a sideways hole in the piston rod to hold the spring, but I am not sure if that was factory or an owner "fix". If the hole is there, use it and a paperclip or a piece of steel wire to hold the spring forward and captive.
With the piston unscrewed, the carrier and bolt can be removed. Reassemble in reverse order. If there is no hole in the rod, I recommend drilling one; it makes assembly much easier.
If you have not fired the gun, try it. Most don't work worth a darn as autoloaders and they are about useless as a pump gun because the shooter has to fight the spring when using the gun in the manual mode. All in all, not an ideal design, but we have to remember that the Standard was the pioneer in gas operation and, for that matter, in pump operated high power rifles as well.
Jim