Swap one of your Summoner Spells to a new, single use Summoner Spell. Each unique Summoner Spell you swap to permanently decreases your swap cooldown by 20s (initial swap cooldown is at 4 mins).
Your first swap becomes available at 6 mins.
Summoner Spells can only be swapped while out of combat.
After using a swapped Summoner Spell you must swap 3 more times before the first can be selected again.