Formatting cells to remove duplicates

I have two part number lists; column A is from a database extraction, column C is extracted from a CAD drawing. My goal is to find all the cells from column C that is not in column A.

I know that there are duplications in both columns. So I sorted each column to remove the blank cells. Then I used the Remove Duplicates command and I noticed that there are still duplicates. Looking deeper I notice the formatting of the cells; text, general, fraction, and number and some numbers start with an apostrophe.

I tried selecting column A and reformatting it to text, but it would not update the cells. If I click each cell to edit then exit it will update to text format. Then I am still stuck with numbers with the apostrophe.

I have attached the file as I start with it.