Step 5: I suppose you don't have a macro...
If you do have one, lucky you, go on and use it. I used a 2/58 SLR lens.
To mount this on the camera I used an adaptor for M42 (42mm metric threading) for my specific camera and and two M42 extension rings.
I already had these for other applications. I use them to mount other lenses on the camera as well as to mount the camera on telescopes.
The M42 extension rings come in sets of three sizes and I saw them on e-bay for less than 10$.
I have a pair of such sets that I got from a flee market a long time ago. Never regretted that buy.
Please do not use any other method to mount a lens on your camera (PVC , cardboard ).
Remember that damaging the interior will cost you much more than a set of adaptors.