From the author's README on Thunderstore

A collection of 16 custom cosmetics created for ReSkate Studio, including fantasy football jerseys, shirts, a hoodie, skateboard graphics, and a hat.

Installation

These are ReSkate Studio .fbmod files. Installing the Thunderstore ZIP by itself may not load the cosmetics into the game.

Download this package and extract the ZIP.
Open ReSkate Studio, configured for your ReSkate installation.
Go to MODS and choose ADD .FBMOD.
Select the included .fbmod files.
Click BUILD & DEPLOY and wait for it to finish.
Launch the game through ReSkate Studio.

Back up your ReSkate Studio project before merging with other cosmetic packs.

Included cosmetics

BMCJersey.fbmod
CLEGuardiansHat.fbmod
CorndogTee.fbmod
DOMDeckGraphic.fbmod
GiantPantherJersey.fbmod
MojoDeckGraphic.fbmod
OCJersey.fbmod
PopOffTee.fbmod
SE7ENTeeBLUE.fbmod
SE7ENTeeGREEN.fbmod
SE7ENTeeORANGE.fbmod
SE7ENTeePurple.fbmod
SSFFLHoodie.fbmod
ShortKingzJersey.fbmod
sjmojoICON.fbmod
sjmojoPC.fbmod

Install SundayStudsCustomCosmetics

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

Open ReSkateLauncher.exe and go to MODS.
Search for SundayStudsCustomCosmetics 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.