How do I edit incorrectly entered w2g info on taxes not yet filed

I had help preparing my 2024 taxes from a veteran advocate who entered all of my w2-g's incorrectly. He completed the filing but we could not e-file. IRS required the documents be mailed instead of e-filing. Now the taxes are complete and need to be mailed in. I want to redo my filing/entries before I actually file. Is there a way for me to remove every incorrect w2-g and re-enter them, receive a new calculation and then file? Again, for clarity, NOTHING has been sent to the IRS as of today. Thank You.