If you can't get any tool under it, try hitting it sideways or parallel with the slot. That will loosen it enough to lift it up. A straight edge will get you very close. That aluminum bar in my photo is what I like to use because it doesn't tip over when you let go of it, unlike a straight edge. It's approximately like using a paper thickness under the bar, because it will just skim across the bar moving it about 1/16" ahead.
I've done it that way many times and the results are just fine. Nothing like a new or sharpened set of blades.... smoooooth.:smile3:
The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)