How long before being deported?

My fianc�e entered on a 90 day visa. Overstayed. Didn't leave in 2005. Was taken in on a minor taffic charge and taken into ice custody 40 hours later. He does not have to serve anytime but he has a forced deportation order his case worker told him. He is in a decent facility has free use of phone privleges etc but we want him back to el Salvador. The ice agent met with him and said if they have to forcefully deport him it would be a month but he could sign and voulenteer to leave. If he signs how long will it be (rough idea) until he's back in el Salvador? He is signing for sure. He wants to voulentary go. Hes been in custody since 10am Monday and ice custody since 9am wed. He thinks they are gonna come back to talk to him within a few days. So when he signs how long will it be?