Disassembly - Voigtlander 50mm F1.5 Nokton Aspherical Leica M mount lens

 This article is a very short guide on opening Voigtlander 50mm F1.5 Nokton Aspherical in Leica M mount - first version with "thin waist" and scalloped focus ring.

Disassembly - Rear area

Unscrew 4 bolts and remove mount ring, then remove DOF scale ring.

Drop acetone to the outer edge of retention ring, let it spread evenly, wait for a minute, then unscrew CCW that ring using rubber cylinder (spanner wrench can work, but don't use force to not damage detents).

Take out RF cylinder, memorize its radial position, CV 50 1.5 has pin on bottom edge so it can be mounted back in only one location

Accurately take out all RF calibration shims.

Drop acetone to the inner edge of retention cylinder, let acetone spread evenly on all circle, then unscrew it. With CV 50 1.5 I'm focusing lens to infinity, holding lens top, pressing that retention cylinder edge on rubber mat, then unscrewing CCW.
Walls a bit thin for spanner wrench and can be easily damaged, so rubber cylinder or rubber mat is preferable.

Disconnect focusing frame, there is socket for silver pin, when assembling should fit.
Once optical frame is separated, there is brass retention ring on the inner wall holding aperture ring in place.

Take out infinity calibration shims