Activate the mana-producing creature by tapping it, adding at least 2.
Activate Yenna by paying 2 and tapping it, creating a token copy of Mirrormade. Choose to have Mirrormade enter the battlefield as a copy of Second Wind attached to the mana-producing creature. Then, untap Yenna and scry 2.
Activate the Second Wind token's second ability by tapping it, untapping the mana-producing creature.