ou can find downloads and reprints of the Kowa 6 shop manual on line.
Google for Kowa and Kowa 6 repair manual and service manual turns up a lot of links to other fourms with people looking for the same, a link to a copy for $28 and link to a link to a link to link that you have to register to download that I do not trust.
I haven't tried Bing or Yahoo but they usually turn up the same results.
Standard procedure for camera servicing is to remove the knobs/levers on the side of the body that the malfunctioning control is on. Knobs are attached with screws, nuts or are left hand thread with access to the fasteners under the covering.
Next start at a corner and carefully lift up the body covering with a hobby knife and fully remove the covering.
The screws that hold the side plate on should be visible
BUT there may be mechanism screws that go through the cover but do not have anything to do with the cover. The plates are usually thin and can be bent/deformed easily.
With the cover removed the associated mechanics or electronics of the camera should be accessible.
Lens/shutter cocking may be in the bottom of the camera with a connecting gear or lever in the side of the body.