Here’s my translation

Alan

“Engi mun ván til,” segir hon “at þú getir komit sáttmáli á með okkr.”
„(There) will (be) no expectation of (it),“ says she, „that you would-be-able to bring a reconciliation to (it, things) between us-two.

“Eigi þiki mér þat vænliga horfa,” segir hann, “því at eigi mun hann því trúa vilja, því at miklu illu hefir þú af stað komit ok margan svikit. 
“That seems (þykkja, present) not to me to look promisingly (adv),” says he, “because he will not want to trust that (ie any reconciliation), because you have brought (koma + dat, Z3) away (exported, committed, handed out?, lit: brought from (the) place) great evil and deceived (pp of svíkja) many (a person)

En við þat má ek leita at fara með þeim boðum sem þú vilt honum gjöra. 
But with that (ie having said that), I can try (leita + inf, Z5) to go with those offers (plural of boð) which you want to make to him.

Eðr ef þú vilt gipta okkr bræðrum systr þínar.”
Or (And-perhaps?) if (in case, in exchange?) you want to give-in-marriage your sisters (acc) to us-two brothers (dat).” (Hint, hint)

“Eigi ætla ek,” segir hon, “at þit sýnist mjök girniligir meyjunum ef þit breytit eigi bragðinu. 
“I expect not,” says she, “that you-two would-seem very desirable to the-maidens if you-two change (breytið, present) not the (your)-appearance (bragð, Z4).

Eðr váru þær girniligar í morgin er þær komu heim. 
But were they (ie the sisters) desirable this (past) morning when they came home? (with the implication that perhaps they weren´t). (I think this makes more sense as a question)

Ok tölum síðar um slíkt. 
And (we) talk later about such.

En þau boð skaltu mega segja honum með fingrgulli því er hann gaf mér fyrsta sinni, at ek gef mik ok allt mitt ríki í hans vald, ok vera hvárt sem hann vill frilla hans eðr eiginkona. 
But (And) those offers (neut acc plural) you-shall be-able to say to him with that finger-ring-of-gold (ie using it as a token of good faith) which he gave to me (the) first time (we met), that I give myself and all my kingdom into his power, and (offer) to be whichever (of the two) he wants, his mistress or (his) wife.

Ok heldr vil ek vera frilla hans en eiga nökkurn þann konungsson er ek veit.”
And I want rather to be his mistress than to have (in marriage) a certain (person), that king’s-son whom I know.”

“Nú skaltu,” segir Hörðr, “láta tjalda hallir þínar á morgin, ok allir þínir menn taki inn besta búning. 
“Now, you-shall,” says Hörðr, “cause to hang-with-tapestries your halls to-morrow, and all your folk (men) take inside (ie enter wearing?) (their) best apparel.

Gangit síðan út á víðan völl ok látit opin öll borgarhlíð. 
Go-(you) (gangið, pl 2 imper) after-that out onto (the) wide field and cause-(you) (látið, imper) all stronghold-gates (to be) opened.

Ok bíðit svá þess sem at höndum kemr.”
And wait-(you) (bíðið, imper) for that such as comes to hands (ie for whatever happens).

Síðan gengr Hörðr í burtu. 
After-that Hörðr goes (on foot) away.

En meykonungrinn breytir nú at öllu svá sem Hörðr hafði fyrir sagt.
But (and) the-maiden-king now makes-changes (breyta Z1, or possibly simply does, breyta, Z4) to everything such as Hörðr had said before (earlier).

16
16.

At morni dags þá er menn vöknuðu gengu menn í vígskörð. 
Next morning early (lit:of (the) day) when folk (men) awoke, folk (men) went (on foot) to (the) ramparts.

Sá menn þá at allr sjár var skipaðr með herskipum. 
Folk (men) saw that all (the) sea (sg) was arranged with battleships.

Var þar þá kominn Ríkarðr konungr faðir Sigrgarðs. 
King Ríkarðr was (had) then come there, father of Sigrgarðr.

Gengu þeir á land ok reistu síðan herbúðir.
They went on to land (ashore) and raised after-that a battle-camp.

Nú er at segja frá Sigrgarði er hann vaknar um morguninn ok var honum þá runnin reiðin in mesta. 
Now (one) is to say about Sigrgarðr when he awakes next-morning and was (had) the-anger (fem nom sg + def art), the-greatest, then run (fem pp of renna, Z4, agrees with reið) from him (ie subsided).

Hörðr kom þar þá ok sagði honum hvat þau meykonungrinn höfðu mælst við. 
Hörðr came there then and said to him what they (he and) the-maiden-king had spoken-to-one-another.

Segir honum ok þat at faðir hans sé þar kominn með óvígan her, ok Gustólfr karl með honum. 
(He) says to him also that his (Sigrgarðr’s) father is (has, subjunctive of indirect discourse) come there with and overwhelming host (unbeatable army), and old-man Gustólfr with him.

Ok sagði at nú væri vildast at þiggja góð boð af meykonunginum. 
And (he) said that now (it) would-be best to accept (the) good offers (plural) from the-maiden-king.

Hann kvað henni eigi sjálfrátt hafa verit um sína illsku.
He declared (it) not have been within her power (e-m er e-t -rátt, sjálfráð, Z3) concerning her wickedness (ie it was not her fault, she was being controlled by external, supernatural forces, lit: it has not been of free-will for her).