Dear Dr. Irma
Maybe others will get what you mean, but I'm sure it will be much easier to help if you upload a photo.
Just upload it to any free image sharing site like imgur or to your dropbox/skydreive whatever then post the link using the "Img" button (it shows itself above when you are writing a post/reply).
Not knowing what you are talking about, it is possible that
A.) the lock is not for disassembly. (At lest you can't do it non-destructively.)
Or B.) when you open the lock and remove the shackle look at the hole from which the shackle is coming. If there is a screw try unscrewing it.
C.) Generally try unscrewing any screw you find on it

Just be careful, it may suddenly fall apart. Than can lead to bits and bobs going missing. Also it can be hard to reassemble a lock if you weren't looking which way and where do things go

PS.: None uses their (scientific) title here, I think it is because it removes a layer of friendliness if we get all official

Unless your doctor's degree is in locks of course
