The problem was I didn't mark the position of the focus ring and front lens. Let's see how I found a solution.
What did I use?
*Unfocused Minox 35MB camera without the focusing ring.
*Focusing ring with it's three screws.
*Black insulating tape.
*Precision knife (X-acto type).
*Matte finish tape (Magic tape).
Hope this will help, the basic procedure could be used in other film camera also.
Step 1: Provide a focusing screen
To do this we sticked two pieces of magic tape to the back of the camera to allow refocusing of a known distance object.