Here’s my translation
Ámundi var fátækr maðr ok bjó, þó hann ætti mikla ómegð.
Ámundi was a poor person (man) and kept-house (búa, Z6), [even] though he had great helplessness (incapacity to support himself)
Hann var Þorkelsson ok þingmaðr Hrafns.
He was [the] son of Þorkell, and a liegeman of Hrafn.
Þorvaldr mælti svá við Kolbein ok hans förunauta, at þeir skyldi beiða Ámunda at fara at Hrafni með þeim, en ef hann vildi eigi fara, þá mæki Þorvaldr, at þeir skyldi vega hann.
Þorvaldr spoke with Kolbeinn and his travelling-companions such, that they should ask Ámundi to attack (lit: go at, <fara at e-m>, Z18) Hrafn with them, but if he wanted not to go, then Þorvaldr spoke (presumably typo for <mælti>) that they should kill him.
Þeir Kolbeinn fundu hann á heyteigi, er hann sló, en kona hans rakaði ljá eftir honum ok bar reifabarn á baki sér, þat er hon fæddi á brjósti.
They, Kolbeinn [and co] found him in a strip-of-a-hayfield, when he cut [the grass], but (and) his wife raked [the] freshly-cut-grass behind him and carried a child-swaddling-bands on her back, that-one which she breast-fed (lit: fed by breast).
Þeir Kolbeinn beiddu Ámunda, at hann færi með þeim á Eyri til Hrafns, en Ámundi kveðst í engri þeiri ferð vera mundu, er Hrafni væri til óþykktar.
They, Kolbeinn [and co] asked Ámundi, that he journey with them to Eyrr to Hrafn, but (and) Ámundi declared-of-himself [that he] would be in no (dat sg fem of <engi>) such (dat sg fem of <sá>, Z2) journey, which was for-the-purpose of ill-will to Hrafn.
Þá hljópu þeir at honum ok vágu hann.
Then they attacked (lit: ran at) him and killed him.
Síðan fóru þeir til fundar við Þorvald ok sögðu honum vígit, en hann lastaði eigi verkit.
After-that they journeyed to a meeting with (ie to see) Þorvaldr, and said (related] the-slaying to him, but (and) he spoke-not-ill of the-deed.
Þá er þeir Þorvaldr kómu í Dýrafjörð, þá fór kona nökkur með skyndingi á Eyri til Hrafns ok sagði honum til fara þeira Þorvalds.
Then when they, Þorvaldr [and co] came to Dýrafjörðr, then a certain womanjourneyed with haste to Eyrr to Hrafn and informed him of [the] journeys of those, Þorvaldr [and co].
Ok er Hrafn heyrði þau tíðendi, þá sendi hann menn til Selárdals til fundar við Eyvind ok bað hann safna liði ok fara til fundar við sik.
And when Hrafn heard those tidings, then he sent persons (men) to Selárdalr to a meeting with (to see) Eyvindr and bade him gather troops and journey to a meeting with (to see) him.
Hrafn sendi ok menn til Barðastrandar til fundar við Steinólf prest Ljótsson ok Gelli Þorsteinsson ok bað þá koma til liðveizlu við sik.
Hrafn also sent persons (men) to Barðaströnd to a meeting with (ie to see) priest Steinófr Ljótr’s-son and Gellir Þorsteinn’s-son and bade them come in support of him.
Þeir Gellir kómu á Eyri með þá menn, er þeir fengu til.
They, Gellir [and Steinólf] came to Eyrr with those men, which they got-hold-of.
Hrafn hafði gert virki mikit ok gott ór grjóti um bæ sinn.
Hrafn had built a great stronghold and good out of stones around his farmstead.
Heimamenn Hrafns bjuggust við kvámu Þorvalds eftir öllum slíkum föngum sem til váru.
[The] members-of-the-household of Hrafn readied-themselves against [the] coming of Þorvaldr by all such means as were available (existed)
Þeir menn, er eigi höfðu bolhlífar aðrar, skáru sér stakka ór þófum.
Those persons (men), who had not other coverings-for-the-body, cut for themselves capes out-of felt.
Þá kvað Sturla Bárðarson vísu:
Then Sturla Bárðr’s-son recited a verse.
hjaldrborðs viðum forðum,
warriors (lit: trees of shields (boards-of-battle)) – formerly -
þjóð bjósk Þróttar klæðum
Folk dressed themselves – of strength (or valour) - in clothes -
þings, gráskyrtur hringa.
of a battle – grey-shirts of rings.
Nú skerr margr í morgin
Now cuts many – this morning -
mótrunnr of sik spjóta,
a meeting-tree over himself – of spears,
mjótt verðr mér at hitta
Narrow becomes for me to hit
mitt hóf, söðulþófa.
Middle-judgement (moderation) – saddle-felt.
[B]: Hamri þæfðar hringa gráskyrtur hlífðu forðum hjaldrborðs viðum. Þjóð bjósk Þróttar þings klæðum. Nú skerr margr spjóta mótrunnr í morgin söðulþófa of sik. Mjótt verðr mér mitt hóf at hitta
Grey-shirts of rings fulled (ie pleated, folded, pp of <þoefa>, Z) by hammer (ie coats of ring-mail) protected formerly [the] warriors (lit: trees of boards-of-battle (ie shields)). Folk dressed-themselves with armour (byrnie-mail or helmet, lit: clothing of a battle (<þing>, Lex Poet 6) of strength (or valour)). Now many a warrior (lit: meeting-tree (<mótruðr>, Lex Poet) of spears) this morning cuts saddle-felt over himself. Middle (<miðr>)-judgement (ie moderation, middle ground) becomes for me narrow (mjór, Z3) to hit (ie hard to strike)
[C]: Hringabrynjur hlífðu forðum bardagamönnunum. Menn færðu sig í brynjur. Nú sker margur maður í dag söðulþófa sér til hlífðar. Mér verður vandratað meðalhófið.
Coats-of-ring-mail protected formerly [the] warriors. Persons (men) conveyed themselves in coats-of-mail. Now many a person (man) today cuts saddle-felt for protection. The middle-course becomes for me hard-to-follow.
Þá var með Hrafni Guðmundr Galtason.
Then (ie at that time) Guðmundr Galti’s-son was (ie stayed) with Hrafn.
Hann var skáld gott ok ódæll maðr ok heldr óargr viðskiptis.
He was a good scaldic-poet and a quarrelsome person (man) and rather wild to deal with (lit: of dealings, <viðskipti>, Z1).
Þat hafði Hrafn mælt, at honum þótti þat líkast í hýbýlum Guðmundr skáld og hundr sá, er Rósta hét, og því reiddist Guðmundr.
Hrafn had spoken that, that that seemed to him most-likely [that] Guðmundr [the] scaldic-poet and that dog, which was-called Rósta [were] in [the] homestead, and Guðmundr got-angry at that.