Guild Wars 2

If I put Rune before AR in ascended iten it doesn´t accept anymore AR I loose a slot.

How can I revert this situation?

ascended armor has 1 socket and 1 infusion slot
a rune will go in the socket
an infusion will go in the slot
infusions could have agony resist, or they could be wvw ones.
I believe all ascended armor has defense infusion slot, so no offense or utility infusions into it (infusions with just AR are omni – they can go in offense or defense infusion slots).
if you want to take a rune out of armor, you can either salvage the armor (you can’t salvage ascended armor) or use a upgrade extractor. neither of these options are viable for any rune you could possible put into that armor. It’s far cheaper just to buy a new rune.

I would like take out the rune with out destroy the ascended armor. Is it possible using upgrade extractor where can I buy it?

Gemstore. But like Mystic said, it’s cheaper to buy a new rune.

unless it’s the superior sigil of generosity or >+9 AR infusion, you can literally buy 3-10 of that rune/sigil for the price of 1 upgrade extractor. (even if you’re buying the gems with $$)