Two notes:

First, I am trying for the second time to post this. The first time was 4 days ago, but I still don't see anything.

Second, I messed up the numbering (I named this 15D, when it should have been 15C, but correcting it would cause too much confusion at this point, I believe.)

And now for my translation:

Hörðr hljóp í milli fóta honum. 

Hordr jumped in between his legs.

Ok vó hann upp á baki sér ok rak hann niðr fall mikit. 

And he fought up his back and pushed him down violently--a great fall.

Losnuðu þá hendr Skjaldar af stönginni.

Then Skjaldr's hand got loose from the staff.

Þá kom gradhestrinn ok greip í hárit á Herði með tönnunum ok sykti honum til falls ok dró hann eptir sér. 

Then the castrated horse came and seized Herdr in the head with its tongue and (sykti?) him to fall and dragged him after itself.

Hrossin öll komu þangat ok vildu bíta Hörð. 

The horses all came there and wanted to bite Hordr.

Hann komst seint á fætur, en hvar sem þau kiptu til hans þá festi hvergi tennrnar á honum, en ef þau slogu til hans þá kiptu sjálf fótunum ok lysti eigi at slá optar enn um sinn. 

He slowly came to his feet, but wherever they pulled at him, then each one fastened its teeth on him, and/but if they struck at him then they pulled themselves his feet and didn't desire to to hit more often still around him.

Skjöldr hleypr þá þangat. 

Skjoldr then runs there.

Þá kom Knútr fram úr skóginum. 

Then Knutr came out of the forest.

Hleypr þá til móts við Skjöld. 

He then runs at Skjoldr.

Skjöldr laust þá til hans með stönginni. 

Skjoldr then strikes at him with the staff.

En hann laust í móti með kylfunni. 

And he struck in return with his club.

Ok var þá hvárgi þeira svá næri öðrum at eigi mátti höggunum við koma. 

And it was then (that) neither of them was no near the other that the blows could not touch (i.e., land)

Gripust þeir þá ok váru þá harðar sviptingar. 

They then grasped each other and then there was hard wrestling.

Eigi mátti Hörðr honum björg veita þvíat hrossin óþægðu honum, en hann ók við hlaununum ok vildi þeim eigi mein gjöra.

Hordr could not give him help because the horses vexed him, and he also with (hlaununum?) and didn't want them to do harm.

Þeir Knútr ok Skjöldr gengust nú at svá at þursinn óð jörðina til knjá. 

Knutr and Skjoldr were now altered so that the ogre waded through the earth to his knees. (??)

Ok varð Knútr sýnt orkuvana fyrir honum. 

And Knutr was clearly bereft of strength against him.

Þessu næst kom Stígandi fram úr skóginum með svínaflokkinn. 

Thereupon Stigandr reappeared out of the forest with the herd of swine.      (Z. fram 1: koma fram = reappear)

Hann sneri þangat til sem þeir áttust við Skjöldr ok Knútr. 

He turned to where they were fighting with Skjoldr and Knutr.

Hann krækti svíðunni í huppinn á Skildi ok sökk hon á kaf. 

He hooked his halberd in Skildr's hip and and plunged it down.

Hann rykkti at sér ok skar út úr ok lágu þar þarmarnir. 

He pulled (the halberd) to himself and cut out from, and his intestines lay there.

Röktust þeir þá úr honum ok lágu þar á króknum. 

They then unwinded out of him, and they lay there on the hook.

Fellu þá út iðrin. 

Then the entrails fell out.

Hann greip þá í eyrat á Knút ok reif þat af honum. 

He then grabbed the ear of Knutr and tore it off him.

Fell Skjöldr þá.

Skjoldr then dropped dead.

Þá kom Hörðr at ok rasaði sér ofan á hann ok svá á brjóstit á honum, ok brotnaði þá í honum hvert bein.

Then Hordr came against and rushed himself headlong down to him and so to his chest, and then broke in him every bone.

Var nú unnin þessi þraut. 

This hard struggle was now won.

En þeir váru bæði sárir ok móðir. 

But there were both wounded and dead.

Dreifðu þeir þá öskunni yfir hrossin. 

They then scattered ashes over the horses.

Flókatrippit hljóp undan. 

The young horse with the matted coat ran away.

Komust þeir Knútr ok Hörðr hvergi á mitt skeið við hana.

Knutr and Hordr came to the end, each in the middle of a race with it.