Schmid Neuchatel-type Perndulum clock – replacing mainspring problem

[boblalux]

Hi everyone
I am trying to replace a damaged spring, but cannot open the case (see photos below). I cannot remove side A or B, whichever is necessary. From Photo 1 you can see that I managed to open about 1mm, but no further. What to do? Must I push axle A -> B direction, or B -> A direction?
Thanks for any advice
Bob

[oldhippy]

Not very clear at the ratchet side, the ratchet should be held in by a pin, remove the pin the ratchet should come off and so should the cap. 

[boblalux]

The pins are fixed. I attach Foto4 of the ratchet side.

[oldhippy]

You need to file off one side and tap it out. 

[boblalux]

Sounds a bit radical ... file off one side of what?

[oldhippy]

The pin has been taped over to form a head you need to file off the head in order to remove the pin, it has been done like that to prevent it from coming out. 

[watchweasol]

Iam sure Old hippy is on the money. I remember reading some time ago about these barrels. A new pin fitted on reassembly and trimmed.

[boblalux]

Many thanks.  The problem has now been resolved by tapping B->A harder than previously dared

[oldhippy]

Just make sure when you put the barrel back together you don't have to much play, if you do the teeth will mesh at a funny angle and will wear one side down not only the barrel teeth but the next wheel.