Here’s my translation

Alan

En Hrafn sagði, at hann mundi til taka með guðs forsjá ok þeira atkvæði. 
But (And) Hrafn said, that he would begin (proceed with it, do it, <taka til>, Z12) with God´s foresight and their decree (decision, <atkvæði> Z4).

Ok þá fór hann höndum um hann ok kenndi steinsins í kviðinum ok færði hann fram í getnaðarliðinn, svá sem hann mátti, ok batt síðan fyrir ofan með hörþræði, svá at eigi skyldi upp þoka steininn, ok öðrum þræði batt hann fyrir framan steininn. 
And then he (Hrafn) stroked him (the patient) with (healing) hands (lit: went with arms all over him) and felt the-stone in the-abdomen and conveyed it forward into the-penis (lit: the-conceiving-joint), such as he could, and bound after-that above [it] with linen-threads, so that [one] should not move the-stone (accusative) up, and with another thread he bound in the front of the-stone (ie between the stone and penis tip).

Ok þá bað hann, at allir skyldu syngja fimm pater noster, þeir er inni váru, áðr hann veitti atgerðina. 
And then he asked, that all should sing five ‘our fathers’, those who were inside, before he performed the-surgical-operation.

Ok síðan skar hann um endilangt með knífi ok tók í brott tvá steina. 
And after-that he cut lengthways with a knife and took away two stones.

Síðan batt hann viðsmjör við sárit ok græddi hann, svá at hann varð heill. 
After-that he bound ‘wood-butter’ against the-wound and healed him so that he became (ie was) healed (hale).

Torvelt er at tína öll ágæti íþróttligrar lækningar hans, þeirar er guð gaf honum. 
[It] is difficult (<torveldr>, Z1) to recount all his exceedingly-skilful healing-arts, those which God gave him.

En fyrir því má slíkt eigi undarligt sýnast, at guði eru engir hlutir ómáttugir, ok af guði er öll sönn lækning, svá sem Páll postuli segir: alii gratia sanitatum in eodem spiritu. 
But (And) such may not seem wonderful for that [reason], that no things are without-strength (although <impossible> ie <úmáttuligr> Z2 would seem to make more sense here) to God, and from God is (ie emanates) all [the] true healing-art, such as (the) apostle Paul says:  To another [the] gifts of healing by [the] same spirit (1 Corinthians 12-9)

Þat er svá at skilja: sumum mönnum er gefin miskunn heilags anda. 
That is to translate thus: [The] Grace of the holy spirit (ghost) is given to some people.

Mörgum mönnum veitti Hrafn smíðir sínar, ok aldri mat hann þær fjár. 
Hrafn performed his works-of-skill for many people (dative), and he never charged money for them (ie his skills) (never put a price on them).

Bæ sinn á Eyri byggði hann vel ok gerði þar mörg hús ok stór ok marga aðra bæjarbót, þá er mikil merki má á sjá.
He settled on his farm in Eyrr well and built there many and large farm-buildings and many other farm-improvements (farm -repairs? <boejar> + <bót>), [of] those which (one) may behold (look on) [the] prominent remains (<merki>, Z4).

5. Frá Markúsi á Rauðasandi.
5. About Markús at Rauðasandr (Red-Sand)

Markús hét maðr. 
[There] was a person (man) called Markús.

Hann var Gíslason, Þórðarsonar, Úlfssonar. 
He was [the] son of Gísli, son of Þórðr, son of Úlfr.

Guðríðr hét móðir Markúss. 
[The] Mother of Markús was-called Guðríðr.

Hon var Steingrímsdóttir. 
She was [the] daughter of Steingrímr.

Ingibjörg hét kona Markúss. 
[The] wife of Markús was-called Ingibjörg.

Hon var dóttir Odds af Söndum ór Dýrafirði. 
She was [the] daughter of Oddr of Sandar (Sands) out-of Dýrafjörðr (Fjord of Wild Animals)

Þau Markús ok Ingibjörg fluttu sik af Söndurn ór Dýrafirði ok til Saurbæjar á Rauðasandi ok bjuggu þar ok áttu tvá sonu ok eina dóttur, svá at ór barnæsku kæmist. 
They Markús and Ingibjörg conveyed themselves from Sandar (Sands, presumably typo for <söndum> ?) out-of Dýrafjörðr and to Saurbær (Mud-farm) at Rauðasandr (Red Sand) and dwelt there and had two sons and one daughter, so that [they, the children] brought-themselves out-of childhood (ie attained, reached adulthood).

Gísli hét sonr þeira inn ellri, en Magnús inn yngri, en Hallbera dóttir. 
Their son, the elder [one] was-called Gísli, but (and) Magnús the younger [one], but (and) [their] daughter Hallbera.

Loftr hét son Markúss. 
[There] was a son of Markús called Loftr.

Hann var laungetinn. 
He was illegitimate

Ragnheiðr hét móðir hans. 
His mother was-called Ragnheiðr

Hon var Bjarnardóttir. 
She was [the] daughter of Björn.

Markús var búþegn góðr ok mikill atferðarmaðr. 
Markús was a good farm-thane (freeman) and a great man-of-energy

Hann fór utan ok lét höggva í Nóregi kirkjuvið góðan. 
He journeyed abroad and caused to hew in Norway good church-timber.

Síðan fór hann út hingat ok kom í Austfjörðu í Gautavík ok gaf kirkjuviðinn allan Sigmundi Ormssyni. 
After-that he journeyed out hither (ie to Iceland) and came into Austfjörðr in Gautavík and gave all the-church-timber to Sigmundr Ormr’s-son

Sú kirkja stendr nú austr á Valþjófsstöðum.
That church stands now east at Valþjófsstaðir.