How to Mega Evolve your Pokémon — Pokémon GO Help Center

When you’ve collected enough Mega Energy, go to an eligible Pokémon’s summary page and tap “Mega Evolve.” You can also Mega Evolve a Pokémon

Pokémon Masters: How To Evolve & Mega Evolve Your Pokémon

Mega Tyranitar Pokémon GO Raid Battle Tips

Can Search by Mega Level : r/TheSilphRoad

what will happen if I mega evolve this? will it keep the costume

Battle With Mega Evolved Pokemon In Pokemon Go's Next Battle Day

Mega-evolutions infographics : r/TheSilphRoad

Mega Evolution, Essentials Docs Wiki

Pokemon Go: How to Get Mega Energy to Mega Evolve

A Guide to Mega Evolution in Pokémon GO