If you get a lawyer, can you get guilty charges expunged in TN?

I have some charges that I plead guilty to that I want to get expunged. I tried to do them myself but they told me that i couldn't do it. I talked to a lawyer that said that he could get them erased but i don't know if he was just trying to say that just to get some money out of me or not. Ive also talked to other people who said that i still should be able to get them expunged and that i just have to go about it a different way. Please tell me anything that you might know about this. thanks