This post was from a user who has deleted their account.
From what I've read/seen, the amount of stats you will be able to change is limited to 30% of the stat you are changing.This is from the PTR patch notes :ReforgingPlayers can now visit special Reforging NPCs in capital cities located near Enchanting trainers. 40% of any one secondary stat on an item can be can be allocated to add a new secondary stat to the item. The stat being added cannot already exist on the item. An item cannot have more than one reforged stat at a time, though the Reforging of an item can be undone and changed..