From the author's README on Thunderstore

akia's cosmetic pack 1 for ReSkate Studio thanks for downloading, this is just a dump of cosmetics made over the past day, more to come.

-HOW TO INSTALL THIS PACK-

1- Download and install ReSkate Studio - https://tinyurl.com/reskatestudio

2- Chose your ReSkate install folder during setup

3- Click on the 'MODS' tab left of the window

4- Click 'ADD .FBMOD' and select all the of the .fbmod files included in this pack

5- Click 'BUILD & DEPLOY' to load your files (this make take a few minutes be patient)

6- Click launch in the top right of the window

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 akias RESKATESTUDIO Cosmetic Pack 1

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

Open ReSkateLauncher.exe and go to MODS.
Search for akias RESKATESTUDIO Cosmetic Pack 1 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.