Step 4: (1) Stabilize the finderscope
The finderscope can be a cause of frustration. This specific one is a 6x25 (6 times magnification , 25mm objective diameter) which will do. It is supported with three screws, one of them containing a spring. The view through it is rather disappointing because the objective is a plastic lens and diffuses light too much, however it is usable as a finderscope when you focus on a bright star.
The major problem is that if you loosen two of the screws to align , it may slide in its holder and this can be a problem in the middle of the night. I used two zip ties to restrict the movement along the tube and also mounted a piece of plastic foam on the body of the finderscope with 2-sided adhesive tape. Problem solved.