From the author's README on Thunderstore

John Cena Kit - As requested this pack is now an easy install through the ReSkate Launcher!

-Enjoy DISCLAIMER: When using with other packs or 'Projects' inside of ReSkate Studio be sure to save your project to avoid issues. Adding other users Projects may not allow you to combine all files in one load.

Install JohnCenaKit

You need ReSkate and your own copy of skate. on Steam.

Open ReSkateLauncher.exe and go to MODS.
Search for JohnCenaKit and click install. The launcher also installs anything it depends on.
Press PLAY. In game, the MODS tab of the ReSkate menu (Insert) turns it on and off.

Or install it by hand: download the .zip and drop it on the launcher window, or unzip it into its own folder in Mods\ beside Skate.exe.

Maps show up in the ReSkate menu's level list. To join a server running a custom map, you need the same map installed. If the game won't load after installing, see known issues.

skatemods doesn't host or review this mod. The download comes straight from Thunderstore. Only install mods you trust, because scripts can run code.