1.    Open Steam.
2.   Hover your mouse over your Steam name next to Community.
3.   Click on Content.
4.   Click on Workshop Items.
5.   On the right side, click Subscribed Items.
6.   If you have a lot of games you can filter the list by game by clicking 'select a game' at the top.
7.   Unsubscribe from the mods on the server.
8.   Go to your Steam Library.
9.   Right Click Ark and hit properties.
10. Click on Local Files and then Browse Local Files.
11. Now navigate your way to ShooterGame -> Content ->Mods.
12. Then delete all the files/folders in this directory by right clicking on the mods directory and choosing delete.