From the author's README on Thunderstore

Ilios (Overwatch)

Ilios from Overwatch, converted into a skateable map for skate. using ReSkate.

Version of the map: Morning, Control layout
Size: the full playable map, including spawn rooms

How to play

Install with a mod manager, or copy this folder into your ReSkate Mods folder.
Start the game through ReSkate and pick Ilios from the map list.

Notes

This is a fan conversion. Some signs, windows and plants may look different from the original.
Report problems on the mod page.

Credits

Map and art: Blizzard Entertainment (Overwatch)
Built with ReSkate Studio

This is an unofficial fan project and is not affiliated with or endorsed by Blizzard Entertainment or Electronic Arts.

Install Overwatch Ilios

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

Open ReSkateLauncher.exe and go to MODS.
Search for Overwatch Ilios 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.