By getting one of the six Crystal Raid Skills from Expert Missions. Brainwash Attack, Marbling Drop, Peeler Storm, Bloody Sauce, Rage Saucer, and Gigantic Ki Blast.
Yeah, you must first collect all Dragonballs, then wish for " I want to become a Super Saiyan God". Next, max out Friendship of all five inspectors: Goku, Vegeta, Gotanks, Pan, Gohan & Vidal. Then talk to Beerus.