> "Njóta skalt þú Þorgils bróður þíns á Reykjahólum að eg vil gera þér

njósn

> `You shall enjoy-the-benefit-deriving-from (for-the-sake-of?)

Þorgil, your brother, at Reykjahól, that I will send-intelligence (see
göra njósn e-m, Z2)

That's right. MM & HP have "for the sake of".

> "Ekki skulum vér ríða að síður," segir Guðleifur, "til fundar við hann."
> 'We shall not ride on less,' says Guðleif, `to a meeting with him.'

That's to say, as the context implies: "We shall ride to meet him none
the less" (=Vér skulum ríða ekki að síður).

> Þangbrandur skaut spjóti í gegnum Þorvald en Guðleifur hjó á öxlina

og frá ofan höndina og var það hans bani.

> Þangbrand shot with a spear through Þorvald but Guðleif hewed onto

the shoulder and below the arm and that was his death.

Or more simply: "Þangbrandr threw a spear through Þorvaldr, and
Gudleifr hewed through his shoulder and down [through] his arm [...]"

MM & HP: "G. hacked his arm off at the shoulder"