If you have your only pack of Instax film loaded in a camera or printer and you want to use it in another camera or printer. You can of course, just take the pack out and move it to another camera or printer and you will only lose the top sheet of film, as the camera or printer you move the pack to will treat the top sheet as a dark slide and will expel that sheet. However, you can also safely take the pack out without losing any sheets of film. All you need to do is to put the dark slide back into the pack. I did this by turning off the lights and taking the pack out, I then slid the dark slide back into the pack and I did not lose any sheets when I moved the pack, because the printer ejected the dark slide when I switched the printer on. Obvious I know, but, I thought people might find it a useful idea.
If you have any Instax tips, please feel free to share them in the comments below.