:1)You can use the green ball which is marked Down grade to upgrade your Evo. level for free, and you only have three times to use it.
2)use Ew-Elixir to upgrade your Evo. level .you need 1000 Diamond. And you have 20 times a day.
3)use the Ew-Elixir X to upgrade your Evo. level . you neeed 9998 Diamond every time. And you only have 4 times a day.