From the author's README on Thunderstore

This took lots of tweaking to actually make it fun to skate on and look pretty but here it is.

Installation

Requires skate. with ReSkate installed.

Install the package through the ReSkate launcher and enable it under Mods. For manual installation, extract the ZIP into its own folder under <Skate folder>/Mods/, then enable the mod in ReSkate.

Select Boom Karts - Skate Park in the map menu.

Install Boom Karts Skate Park

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

Open ReSkateLauncher.exe and go to MODS.
Search for Boom Karts Skate Park 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.