Does anyone know how two atheists can marry?

Marriage is a legal joining of two people - religion does not need to be involved.

A judge, justice of the peace, notary, or anyone else who is certified to perform marriage ceramonies can legally marry you. You must get a marriage license from your local court house and fill out the proper paperwork. Most states have a waiting period of 2-3 days after you recieve your marriage license before you can actually have the ceremony and get married.

You can have a wedding just as any religous person would. Find a venue (rental halls, outdoor wedding, town hall, etc) and have a ceremony. It is exactly the same with exhanging vows, just the religous aspect is not a part of it.

You can also just get your license and get married by a judge, notary, justice of the peace, etc and not have an actual wedding. Me and my husband were married by a Notary. It was just me, him, and the woman marrying us.