So the army killed them should not be difficult to translate.

And Demetrius took his seat upon the throne of his kingdom: Goldstein translates the meaning of this clause very well, saying “and Demetrius became undisputed king.” Good News Bible also conveys the meaning fairly well, and so does Contemporary English Version with “and he took command of the whole kingdom.”

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Maccabees. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here.