Here’s my translation

Alan

Þeir fóru Glámuheiði til Arnarfjarðar. 
They journeyed [ie passed along] Glámuheiðr to Arnarfjörðr

Ok er þeir kómu ofan í fjörðinn til byggða, þá bundu þeir alla menn á bæjum, þar sem þeir kómu, at engi væri njósn borin fyrir þeim til Eyrar, en þeim, er í böndum váru, þótti þung sín ævi, en börn grétu, er bundin váru, en mæðr eða feðr máttu eigi duga þeim, þar er allir váru bundnir. 
And when they came down into the-fjord to [the] inhabited-districts, they bound all persons on farms, wherever they came, [so] that no news (<njósn>, Z2) would-be borne before (ie in advance of) them to Eyrr, but (and) to those, who were in fetters (bonds), their-own life-story seemed heavy (ie oppressive), but (and) children cried, who were bound, but (and) [their] mothers (<moeðr>, plural)  and fathers (plural) could not help them, there where all were bound.

Á einum bæ, þar er menn váru bundnir, hétu þeir á Þorlák byskup til þess, at þeir skyldi lausir verða. 
At one farm, there where persons were bound, they appealed to (invoked) bishop Þorlákr (accusative) to that [end], that they should become [ie be] freed.

Þeir hétu söngum. 
They appealed (invoked) by (means of) songs (singing) (instrumental dative).

Ok er þeir höfðu fest heitit, þá spruttu bönd af einum þeira, ok leysti sá alla, ok síðan fóru þeir á bæi, er menn váru bundnir, ok leystu menn ór böndum. 
And when they had made-fast (pledged, pp. of <festa>) the vow (invocation, <heit>, noun + def. art.), then [the] fetters (pl. of <band>, Z3) of one of them broke, and that-one (ie he) released all, and after-that they journeyed to a farm, where persons were bound, and released persons out-of [their] fetters.

Hrafn var vanr at láta vaka yfir bæ sínum ok halda vörðu, en þat kveld, er þeir Þorvaldr höfðu komit af heiðinni, spurði Hrafn heimamenn sína, hvárt þeir vildi eigi halda vörð, en þeir svöruðu ok kváðu eigi mundu þurfa vörð at halda, er fjúk var úti, sögðu ok, at eigi mundu menn gera til þeira um langaföstu. 
Hrafn was accustomed to cause to keep-a-night-watch over his farm and to maintain a watch, but (and) that evening, when they, Þorvaldr [and co] had come from the-heath, Hrafn asked his servants, whether they wanted not to maintain watch, but (and) they answered and declared [that they] would not need to maintain watch, when [there] was a drifting-snow-storm outside, [and] said also, that persons (I presume this means Hrafn’s men?) would not prepare (get ready) for them  (I presume this means Þorvaldr and co? rather than the other way round) during Lent (lit: long-fast).

Hrafn sagði: "Þat þykkir mér ráð, at haldinn sé vörðr í nótt." 
Hrafn said: “That seems to me wise-council, that a watch be maintained to-night.”

Þangat til hafði vörðr haldinn verit hverja nótt, en þá nótt var eigi vörðr haldinn, er þeir Þorvaldr kómu. 
Till that time, a watch had been maintained each night, but that night, when they, Þorvaldr [and co] came, a watch was not maintained.

Þá er Hrafn var kominn í rekkju, mátti hann eigi sofna. 
Then when Hrafn was [had] come to bed, he could not get-to-sleep.

Hann mælti við mann, þann er Steingrímr hét, at hann skyldi kveða Andreasdrápu. 
He spoke with that person (man), who was-called Steingrímr, that he should recite Andreasdrápa (Poem in praise of St. Andrew)

Hann kvað drápuna, ok eftir hvert erendi talaði Hrafn margt um þá atburði, er gerzt höfðu í písl Andreas postula. 
He recited the drápa (laudatory poem), and after each stanza, (<örendi>, Z2) Hrafn talked many-(a thing) concerning those incidents, which had happened in [the] passion of Andrew [the] Apostle (St Andrew).

Þá nótt dreymdi Tómas prest Þórarinsson, at hann þóttist sjá písl Andreas postula. 
That night [the] priest Þórarinn’s-son, that he bethought-himself to see [the] passion of Andrew [the] Apostle (St Andrew).

Þat sama dreymdi hann alla nóttina, jafnan er hann sofnaði. 
That same [occasion] [it] appeared-in-a-dream to him all night, always when he fell-asleep.

Þá nótt kom Þorvaldr á Eyri. 
That night came Þorvaldr to Eyrr.

Ok er þeir kómu at virkinu, þá settu þeir mann þann, er Bárðr hét, á skjöld ok lyftu skildinum upp á spjótaoddum á virkit. 
And when they came to the-stronghold, then they placed that person (man), who was-called Barðr, on a shield and lifted the-shield up on spear-points on to the stronghold.

Síðan tók hann til við lás duranna ok renndi frá slánum, þeim er váru á virkishurðunni, ok lauk upp virkinu. 
After-that he took to [it] with (ie began to work on?) [the] lock of the-door and let-run (let loose) from [it, ie the lock] those cross-beams (bolts) (ie the cross-beams were let loose from the door-lock, <renna>, Z4 could be either direct or impers. I think), which were on the-door-of-the-stronghold, and opened up the-stronghold.


Þá gekk Þorvaldr í virkit ok förunautar hans. 
Then Þorvaldr went into the-stronghold and his travelling-companions.