The disassembly of Valmet rilfes is pretty much the same as for any AKrifle. 

One major improvement of Valmet rifles over other AK series is removal of the gas tube.  On Valmet rifles the gas tube simply slides rightout.  On other AK's, a lever on the side of the barrel trunion mustbe rotated up to allow the gas tube to be removed.

Step 1.      Makesure your gun is UNLOADED.Never assume it is unloaded!  To do this, keep the gun pointed in a safe direction, remove the magazine, and cycle the bolt to the rear.  Look into the chamber to ensure no cartridge is present.

Step 2.    Push in on the Receiver Cover Retainer button.  While the button is pushed in, gently lift the rear of the receiver cover up.  The receiver cover has a lip that fits into the gas tube.  Pull the cover away from the gas tube to clear this lip.

Step 3.    The recoil spring assembly will be the next item removed.  The rear of the recoil spring is secured in a notch in the receiver.  The recoil spring assembly must be pulled forward and turned slightly to remove it from this notch.  After this is done, pull the recoil spring assembly to the rear.

Step 4.    Make sure the safety is in the fully down position.  Grasp the bolt carrier with your hand and guide it to the rear slowly.  In many Valmets, it is necessary to slide the gas tube to the rear a bit to allow the bolt carrier and gas piston to be removed from the gas tube.

Step 5.    Remove the gas tube by pulling straight back.

You rifle is now ready for cleaning!  It is best to clean a rifle from the chamber than the muzzle.  Do not pull the trigger on your gun while the bolt is out.  The hammer will go all the way forward,impacting against the inside of the lower receiver.  This has happened to me without damage, but it can't be good for the hammer!

Step 6.    To disassemble the bolt, simply rotate the bolt from the bolt carrier, and pull forward.  A good stiff toothbrush is ideal for cleaning under the extractor, and the firing pin hole.

Step 7.    Reassemble your rifle by reversing the above steps.  Enjoy!