The W-2 should include the effect of the adjustment, if the wages were repaid in the same year. There is no procedure on your tax return to claim an offset for a bonus that was repaid in the same year. The company should adjust your box 1, 3 and 5 wages and your box 4 and 6 taxes. If you don't know if your W-2 correctly reflects the repayment, you may need to check with the employer, or maybe take your pay stubs and other information to an accountant to review.
