How to amend W-2c sent from employer

You do not correct a W-2C.  If there is an error on the W-2C then you contact your employer and request another corrected W-2.

To be clear - I received a corrected W-2c from my employer due to  taking taxes out while on workers comp and I am not sure which form to use (1040X) to amend the correction.

Thanks

If you have previously filed the tax return where the original W-2 was reported, then you will have to file an amended tax return, Form 1040X, to report the corrected W-2.

See this TurboTax support FAQ for amending a prior year tax return originally completed and filed using TurboTax - https://ttlc.intuit.com/questions/1894381-how-to-amend-change-or-correct-a-return-you-already-filed