So apparently I wasn't able to acquire 120mm film at local photo stores anywhere here in my place just as I thought. Anyway, knowing the problem I have been reading loads of stuff in the internet and learning the basics of analogue cameras and its innards, I was able to find a way to do 120 cameras with 35mm film and I was kind of bored so... Moreover, what I'm going to show you, I believe, would be applicable to many 120 analogue cameras regardless of the model.
Step 1: WHAT YOU NEED?
1) Holga 120 (any 120 analogue camera)
2) 35mm Film
3) Popsicle Sticks (but you could do it with any material, tongue depressor for example -- anything that can easily be cut to a specified width would work)
4) Pair of Scissors
6) Pencil (any marker)
7) Electrical Tape (any tape would do)
Step 2: WHAT DO YOU NEED TO DO?
1) Cut off a popsicle stick to the same length as the spool on your Holga camera.
2) Trim the excess and make the edge even.
3) Make sure that it fits the film compartment of your camera. The important thing is that it doesn't play around the film compartment. What the popsicle stick is going to do mainly is it's going to fix the 35mm film at the center when we attach the film to it.
4) Attach your 35mm film to the popsicle stick by taping it. Make sure that you tape the film at the center of the popsicle stick.
5) Next thing we need to do is we need to cover up the red window at the back of the Holga or any 120 analogue camera. The reason why we're doing this is because unlike a 120 film, 35mm doesn't have paper backing so that if we ran the film without covering the window it would expose the film.
6) Make sure that you cover the entire window at the back of your Holga.
7) Mount the 35mm film to the film compartment of your Holga.
8) You may want to tape the film to the spool just to make sure that it would not wander around when you rewind it.
9) Turn the knob twice to set it to the unexposed film.
10) Cover the Holga.
After mounting the back cover, you may want to turn the knob twice again and then you're ready to shoot!
If you have any questions, concerns regarding this tutorial you may PM me and I will get back to you as soon as I could.
UNLOADING THE FILM:
Well, you need to do everything in the dark. Check out these film changing bags!
Step 3: Sample Output
35mm, Black and White film test shots...