The phrase “do these things away” seems rather odd to modern readers, and one might suspect a primitive error here. But it turns out that in Early Modern English this phrase meant ‘to put away, dismiss, remove’. This transitive meaning is listed under definition 44a for the verb do in the Oxford English Dictionary. The last quotation cited in the OED with this meaning comes from Edmund Spenser in 1596: “Do fear away and tell.” In the preceding text, Moroni uses this phraseology to refer to those who would deny the power and gifts of God, thus preventing the Spirit from working in their lives:
Summary: Maintain in Moroni 10:24, 26 the use of the archaic phraseology “to do away”, which dates from Early Modern English and means ‘to put away, dismiss, remove’.