In this guide i will show you where you can find the upgrade vendor and how to upgrade(works in TW and KR versions, possibly HK). First off lets find a vendor, they are located in all the big citys for example Kokkara.

Now heres a list of the upgrade stones.
Blue =
Armor
Red =
Weapons
Green= Pure stone for
Armor (Has the chance to upgrade more than once in 1 shot)
Purple= Pure stone for
Weapons (Same as green, but for weapons rather than armor)
Black=
Downgrade the 1st picture here is a weapons
downgrade stone the 2nd one is a armor
downgrade stone.
White stones these prevent breaking after +6.
You can get these items in Auction house or drops from mobs. Also Waguwagu
The "U55" means you upgrade/downgrade any armor up that is up to level 55. If it were U30, you could upgrade any armor to level 30.
After +5 on weapons and +3 on armor you have to pick up 1 card in 3. 1 is broken, 1 is fail and other is success. Also to get past this card game you can use a purple or green stone.
Ok so you have the stone you want to use now so you go to the vendor press the 1st tab and this is what you do
and once your done with that you will see if your item succeeded, failed, or sadly broken.
Now heres how to change properties of an item.
Step 1: Go to the upgrade merchant
Step 2: Go to 2nd tab
Step 3:

Step 4:
If you have info for the new properties system or i missed something please post below.
Also if this guide helped you please press Thank User!