> ok leitaði þar fyrst á, er hann gat þann af ráðit (l. 878). I

would appreciate a literal translation of this line


leita á "attack, make an attempt"
ráða af "get rid of / deal with / remove (an obstacle, a problem)"
geta + past-part. or supine "manage to to, succeed in doing" (In
modern usage, as you know, extended to simply "being able to do").

ok leitaði þar fyrst á, er hann gat þann af ráðit, er honum þótti
þér vera meiri maðr

Lit. "and sought-SG there first on, when he got that-one-M-SG-ACC
away sorted-out, who to-him seemed than-you to-be a-greater-M-SG-NOM
man"

That is: "and only made his move once he'd managed to get rid of the
man he thought was better than you"

LN