Just doing a Google search might be fruitful, if you 're lucky you find model specific instructions. I did it once with an old Kodak. Opening it up is usually not too difficult, removing the filter is super easy too (it's a small, transparent square piece behind the lens). Putting it back together and have all features (zoom, focus etc.) working properly afterwards is sometimes a bit more difficult, but with the Kodak it worked out just fine.