If your list is in a single column, the process is pretty easy.
Add a column to the table containing the list. For the example, I'll assume the list is in column A, the added column is column B, and that the table has one header row.
Click cell B2 to select it, then type = to open the formula editor, and enter the formula below:
COUNTIF(A$2:A2,A2)
Click the green checkmark on the editor to confirm the formula and close the editor. You should see the result, 1 in the cell.
Fill down.
Place the mouse pointer near the bottom edge of cell B2. When the Fill Handle (small yellow circle) appears, place the tip of the pointer on it, Click and hold, and drag down the column to fill the formula into all cells of column B.

Sort:
Select column B, then click the small v that appears when you place the pointer near the right end of the column reference tab, and choose Sort ascending to sort the table by the counts done by the formula.

Select and delete the rows containing a count greater than 1.
Regards,
Barry