If you are referring to the EIN on a W2, follow these steps:

• Under the Federal menu on the left, choose Wages & Income
• Click Edit/Add next to Job (W-2)
• Click Edit next to the W2 you wish to change
• The first box will be the Employer Identification Number (EIN). Make the necessary changes.
• Click Continue

If your question involves a form other than a W2, please include more detail so that we may better guide you.

I already submitted my taxes but enter the wrong ein for my employer do I have to amend 

@Bingoluvr22 It is possible that it will be rejected if you entered the wrong EIN, but you will need to wait until the IRS either accepts or rejects your return before you can amend it.