Warlock's Boots +1  

you have to trade:

* Ancient Beastcoin: 22
* Ruby Silk Thread
* Cardinal Cloth
* Black Tiger Leather
* Warlock boots

to Sagheera, a NPC in port jeuno, near the Windurstian ariship.

If you want your old boots back, you can always redo the AF quests, as you did to get them in the 1st place.

If you wanna check out some more info on this piece and any other, this is where i withdrew this info for:
http://wiki.ffxiclopedia.org/