How do you file 2 w-2 forms?

Add the values and put right in the cells as if they were one. Or, virtually all software handle this easily, asking you the info for each, and combine them itself (making a separate report as/where required).

If your an employer, follow the instructions on the form...there are several other documents and reconciliations that must accompany each, and of course form 941 & 940 info, and many things depedent on the state or cities you and the employees are in. That few a number should not require electronic/magnetic media filing.