The home I bought had a woodburning fireplace that the previous owners converted to a Pellet Stove. I’d rather have a woodburning fireplace. Can I just remove the stove and go back to using the chimney or do I need a professional to do the conversion?

I would recommend you get it inspected by a professional.
It wouldn’t cost much, and he/she will be able to tell you exactly what needs to be done to adhere to your local fire codes.
Then you can do the work yourself, if you feel confident in your abilities.
Some Fireplace inserts call for a specific vent to be run inside the Chimney opening to accommodate the insert.
Others don’t.
I couldn’t be sure if yours is modified unless I looked at it.
Just remember, if it’s not done correctly now, if you ever plan on selling the house, it’s going to be inspected anyway, so you’ll have to pay for anything that was done wrong now, then.
Not to mention the risk to your property and personal safety.
And if you use the fireplace a lot, have it cleaned and inspected periodically.
Be safe..