Can I file a quitclaim deed myself or should I consult a lawyer?

Can you file it on your own - yes, I suppose you COULD.

The better question is, SHOULD you - and to that, I have to say, NO, you should not.  Although drafting a filing a deed is not exceedingly complex, a simple mistake (easy to make if you're not familar with the terminology and procedures) could render the whole thing ineffective.

A local attorney should be able to draft your deed, get it recorded, and provide counsel on the subject (to make sure you understand the consequences of your actions) should only cost a few hundred dollars, which is inexpensive compared to the thousands, if not more, you'd spend if something goes wrong.

You might be able to find a form for this and complete it properly, and have it recorded.  It's called a "quitclaim" deed, by the way.  But a lawyer can make sure it's done right the first time.  I'm assuming the real estate has some real value, and the legal fees now will be a lot less than they will be if you make a mistake and only find out that you have to correct it years from now.  For example, if you find out that your deed didn't work later on, and your sister has passed away in the meantime, you'll have a mess on your hands.

Filing a quit claim deed is not rocket science and can certainly be done on your own with a little bit of research and asking questions of the right people.  You need to make sure that you first have a valid quit claim deed.  If you find a deed on the Internet you are risking that the deed does not comply with IL law.  You do not want to have an invalid quit claim deed as it will only cause problems with the title on the land and may in fact lead to litigation that costs you thousands of dollars.  I suggest that you hire a lawyer to draft the quit claim deed as it should only cost you $700 to get this process complete soup to nuts or even less.  You cannot pay for peace and mind, which is what hiring a lawyer will get you to draft this simple instrument.