You have to remove the shutter from the body, remove the lenses, carefully.
Usually three screws on the back of the shutter housing as per the page chippy posted.
-With some gentle fiddling the back comes off. All the shutter blades might fall out at this point. Some are stuck to the back and some ares stuck to the front. Apparently it is a good idea to note, if you can, where each blade goes. I've had some success with this by making a drawing of the shutter blades and placing the blades in a numbered container of some sort. Egg carton for instance.
-This is a good time to clean and lubricate the timer mechanism. Use lighter fluid to flush completely. Lubricate with
tiny drops of Nyoil (from Microtools
http://www.micro-tools.com/store/item_detail.aspx?ItemCode=NYOIL)
-The iris blades are then obvious, behind a circular plate held by three screws. I've only done this twice before and I found both times that some blades were damaged. So good luck!
-Then to reassemble, clean each blade with alcohol and
gently place them in there respective positions. I like to use plastic (non,magnetic) tweezers. I have had good success by lightly lubricating the ring with light grease. Keep anything off the blades.
Then you must attend to the shutter blades.
-clean these very gently and perfectly with alcohol. When clean do not touch with your fingers as the natural oil on your fingers will show on the blades. It may actually affect the shutter speed.
-assemble using plastic tweezers placing each blade in their respective positions on the back of the shutter timer mechanism.
This is a real bugger, until you do it a few times. Be patient.
Do not lubricate**. Make sure no lubrication can come in contact with the blades from the timer or the iris mechanism.
-replace the housing carefully over the shutter blades with out disturbing the shutter blades. (this is also a real bugger)
Reset shutter speed etc.
No...it isn't easy.
(** I have carefully taken a soft "B" pencil and gently rubbed the fulcrum of the shutter blades on both sides before replacing, to act as a lubricant.)
