We have heard how the battle-weary steed-steerer of trails of keel
defended himself with [his] spear, Gunnar, south of Kjölr.
glað-stýrandi slóða kjalar. steed-steerer of trails of keel (kjölr) =
steerer of steed of trails of keel. The trails of the keel = the sea.
The horse of the sea is a ship. "Steerer of ship" is a kenning for
man/warrior. Here 'glaðr' is a heiti (poetic word) for "horse".
fyrir ... sunnan "south of ...". Likewise other direction words with
'fyrir' before them and the suffix '-an'. In that particular
combination, you don't need to translate it "from the south", "from
the north", etc.
'Gunnar' is in apposition with 'vígmóðr glaðstýrandi slóða kjalar'.
Sóknrýrir vann sára
sextán viðar mána
hríðar herðimeiða
hauðrmens en tvo dauða.
Attack-damager (=warrior) caused to be wounded 16 hardening-trees of
storm of moon of wood of land-necklace (=warriors), and two [to be] dead.
hauðr-men "land-necklace" = the ocean (that surrounds the land as a
nekclace surrounds a neck). viðr hauðrmen "wood of land-necklace" =
ship (wooden object that floats on the sea). Moon (máni) of ship is a
shield, seen as a bright disk adorning the side of the vessel. The
storm (hríð) of the shield is battle. And a hardening-tree
(herði-meiðr) is a man who makes battle harder, fiercer, more intense
by his fighting, i.e. a warrior. Tree is just a conventional base
word in kennings for people; men and women are described using words
for trees with masculine or feminine gender respectively.
For this use of 'vinna' + adjective "to make...", "cause to be...",
see Zoega (10). 'herði-meiða' is accusative plural of 'herði-meiðr';
'sára' is an adjective, accusative plural to agree with 'herði-meiða'.
'tvo dauða' (in standardised Old Norse spelling: tvá dauða) is also
accusative plural, and likewise an object of 'vann'.