Ok, someone help...
https://www.guildwars2.com/en/news/pvp-reward-tracks-and-gear-unification/
All the skins in your PvP locker have now been moved to your Wardrobe in your bank. Whatever you wear into PvP basically turns into a skin there, use the UI located at the center top of your screen to apply PvP runes/sigils/stat amulet and set your PvP traits.
You get new skins from the PvP reward tracks now. For transmutation, all your levels in PvP were converted to transmutation stones, combine them to form transmutation charges and use the wardrobe feature to apply new skins to your gear.