How handy are you? Feel up to it? Do you have a decent set of screwdrivers? If it doesn't work out for you are you preapred to say it was an education n buy another lens? If so go for it!
Organize your screws in a weekly pill organiser n in the same order you take em out so when putting em back you jsut reverse the operation n it all goes where it belongs. Work on a clean well lit surface, preferably a foam mat.
There are a couple varieties of 180s. Some, the front cell comes out like a light bulb just grab it n unscrew it out. Some it will come out after you take off the name ring which unscrews if you can get a good grip on it. Using a rubber glove, a rubber plug that fits will give enough friction to get it out, then the friont cell just unscrews oiut of the cone, then the cones unsccrews.
Once the front cell is out you are ready to get to the shutter. The lens comes appart like a layer cake starting at the top. Unscrew the few screws n the fist layer comes out. Then you'll see another ferw screws n the next layer comes out. Once the 2 layers are out tuirn it over n unscrew the retainer ring, a black ring around the center opening. Put the mirror up button in the M position.
Now the shell half will come off (there may be 3 screws along the top edge on some) n you will be holing the shutter in it's mount in your hand. To get the shutter out of it's mount you will have to take the tin thing off first, then losten the screws to the iris preview slider, then the screw in the center of the mirror up spring. Now you should be able to take the shutter out of it;'s mount.
e-mail; me n I can tell you how to clean the shutter n share some pictures I have.