Here’s my translation

Alan

Rán þat, er Þorvaldr rænti á Eyri, ok önnur þau, er þeir ræntu í Arnarfirði, váru aftr goldin, svá sem skyldi. 
That plundering, which Þorvaldr plundered at Eyrr, and those other [plunderings], which they plundered in Arnarfjörðr, were paid back, so as [one] should (ie as per obligation?).

Þorvaldr fór utan ok gekk suðr til Róms ok var utan þrjú ár, en meðan Þorvaldr var utan, lét Pétr Bárðarson drepa Íma Þorkelsson, en höggva fót undan Jóni Þorsteinssyni, því at þeir höfðu farit með Þorvaldi til aftöku Hrafns ok höfðu eigi fé fyrir sik bætt. 
Þorvaldr journeyed abroad and went south to Rome [on a pilgrimage] and was abroad three years, and while Þorvaldr was abroad, Pétr Bárðr’-son caused to kill Ími Þorkell’s-son, but (and) to hew a leg (with foot attached) from-under Jón Þorsteinn’s-son, because they (ie Ími and Jón) had journeyed with Þorvaldr to [the] slaying of Hrafn and had not paid  (pp of <boeta>, Z2) money (weregild) for themselves (ie on their own behalf, to atone/compensate for their own part in the matter).

Þorvaldr kom út, þá hann hafði þrjá vetr utan verit ok gengit suðr, ok bjó síðan í Vatnsfirði, meðan hann lifði.
Þorvaldr came out (ie returned to Iceland), when (<þá> = <þá er>, Z5) he had been abroad three winters and [had] journeyed south [on his pilgrimage], and dwelt after-that in Vatnsfjörðr, while (as long as) he lived.

20. Frá niðjum Hrafns.
20. About [the] kinsmen of Hrafn.

Þessi váru börn Hrafns Sveinbjarnarsonar ok Hallkötlu Einarsdóttur, þau er ór barndómi kómust: Einarr ok Grímr, Sveinbjörn ok Krákr, Steinunn ok Herdís, Hallgerðr ok Þuríðr.    
These were [the] children of Hrafn Sveinbjörn’s-son and Halkatla Einarr’s-daughter, those who made-their-way out of childhood: Einarr and Grímr, Sveinbjörn and Krákr, Steinunn and Herdís, Hallgerðr and Þuríðr.

Einarr ok Grímr týndust við Grímsey af kaupskipsbáti. 
Einarr and Grímr were-lost (and hence perished) from-off a merchant-ship’s-boat by (ie off the coast of) Grímsey (Grímr’s-Island).

Sveinbjörn ok Krákr fellu á Örlygsstöðum með Sturlu ok Sighvati. 
Sveinbjörn and Krákr fell (in battle) at (the battle of) Örlygsstaðir (Örlygr’s-steads) with Sturla (Sighvatr’s-son) and (his father) Sighvatr.

Steinunni Hrafnsdóttur átti Oddr Álason, ok var þeira sonr herra Hrafn, Óláfr ok Guðlaugr. 
Oddr Alí’s-son (nom) had (in marriage) Steinunn Hrafn’s-daughter (acc), and their son was a ‘Lord’ Hrafn, [and their other children were?] Ólafr and Guðlaugr

Herdís var ok dóttir þeira Odds ok Steinunnar, er átti Svarthöfði Dufgússon.  
Herdís was also a daughter of them, Oddr and Steinunn, whom Svarthöfði Dufgúss’s-son had (in marriage).

Herdísi Hrafnsdóttur átti fyrr Eyjólfr Kársson, ok var þeira sonr Eyjólfr, er fell á Þverárfundi, inn vaskasti maðr. 
Eyjólfr Kár’s-son had (in marriage) Herdís Hrafn’s-daughter sooner [than any of her other marriages] (ie her first marriage), and their son was Eyjólfr, who fell (in battle) at Þverárfundr (Battle of Side (Tributary)-River), the most-valiant of persons (men).

Síðan átti Herdísi Sigmundr Gunnarsson. 
Afterwards, Sigmundr Gunnarr’s-son married Herdís.

Þeira sonr var Sveinbjörn, faðir herra Eiríks, Krákr ok Steinunn. 
Their son was Sveinbjörn, father of ‘Lord’ Eiríkr, [and their other children were?] Krákr and Steinunn

Hallgerði Hrafnsdóttur átti Víkarr Þorkelsson. 
Víkarr Þorkell’s-son had (in marriage) Hallgerðr Hrafn’s-daughter.

Þeira sonr var Grímr, faðir Einars, Más ok Víkars, ok Hrómundr læknir, faðir Kráks læknis í Hvallátrum ok Víkars ok Þórðar.
Their son was Grímr, father of Einarr, Már and Víkarr, and Hrómundr [the] physician, father of Krákr [the] physician in Hvallátrar (Whale-Nurseries, see <látr>, CV) and Víkarr and Þórðr.

Þuríði Hrafnsdóttur átti Helgi Sveinsson, er fell á Örlygsstöðum. 
Helgi Sveinn’s-son, who fell (in battle) at (the Battle of) Örlygsstaðir (Örlygr’s-steads), had (in marriage) Þuríðr Hrafn’s-daughter.

Þeira börn váru: Guttormr, Gautr, Vilhjálmr ok Einarr, Margrét ok Gunnhildr. 
Their children were Guttormr, Gautr, Vilhjálmr and Einarr, Margrét and Gunnhildr.

Guttormr átti Þorgerði Þorláksdóttur, systur Árna byskups. 
Guttormr had (in marriage) Þorgerðr Þorlákr’s-daughter, sister of bishop Árni.

Vilhjálmr átti Marínu Þorkelsdóttur, Margrétu átti Valdi, Gunnhildi átti Steinólfr Ísleifsson, faðir Þorsteins ok Magnúss ok Jóns ok Herdísar, móður Einars Bergssonar..
Vilhjálmr had (in marriage) Márina Þorkell’s-daughter, Valdi had (in marriage) Margrét, Steinólfr Ísleifr’s-son had (in marriage) Gunnhildr, [the former being] father of Magnúss and Jón and Herdís [who was] mother of Einarr Berg’s-son.