Nigel
I used the wet the area approach.
I didn't see the comment about the slip of paper approach when I did it originally, although I think I can see how this could be just as effective without wetting everything. One thing I can see might cause problems with this approach is if the paper does break, getting the broken piece out again might be fiddly. A pair of tweezers might come in handy in this case.
Now if only I could use alcohol to fix the broken part on my OM1, I'd be a happy man.
Mike