Perhaps, he can't! We need more information. The El Savador program was not an amnesty. It was NACARA. If his lawful permanent resident status was rescinded, because he lied, and he was ordered deported, then he may have a permanent bar to immigration. This bar is based upon Section 212(a)(6)(C)(i). Whether he can somehow obtain a waiver of the permanent bar depends upon whether his U.S. Citizen Wife can prove that she will suffer extreme hardship with enough evidence.
If his wife can live with him in Guatemala, merely with the suffering occasioned by someone whose spouse was deported, then this may not be enough. The fact that this is a permanent bar may allow more reasonable evaluation of the future hardship that she will likely suffer. However, there are other concerns.
Has he ever returned to the U.S after a deportation order? Did the DHS have to deport him, because he refused to leave on his own? If so, either of these facts can create complicate, delay or prevent his return.
His wife should contact a very experienced immigration attorney.
The above is general information and does not create an attorney-client relationship.