LE has some great new armor for all professions. These are considered to be the armor to get between Tier 3 and Combined Alien Armor.
This armor is however available at all qls, unlike Tier 3, so some parts would be beneficial as replacements for tier 1 and 2 at different levels. Also, some ql 300 might be better than combined for certain professions, as some fully upgraded pieces add a huge boost to some stats.
The process of upgrading them is the same as upgrading weapons. You will need bio-material, which drops from the new Alien mission bosses. Here is the full list of clumps.
Just like the weapons, the upgrading process is simple. Just like the weapons, the mesh changes with certain upgrades. There are no tradeskills involved. Simply add a clump, that must be at least 80% the ql of the Armour!