It's pretty simple, first you're gonna need to download either the Updated Cube World Alpha[drive.google.com] where the Glider Glitch is patched, or the Original Cube World Alpha[drive.google.com] with the Glitch. When you bought the game on Picroma you should be able to download the Original version without patch there. Please do not download the game if you didn't buy it. With the Updated version, you can also install the Cube World Essentials Modpack[cdn.discordapp.com] With all that done, you can go to the next step and delete all the files in your Steam\steamapps\common\Cube World folder, but not the folder itself. Then you open the Alpha files you downloaded, rename Cube.exe to cubeworld.exe and move all the files in the Steam Cube World folder.
That's it, now you can play with Steam overlay, cloud, make photos with F12 and you see your playtime. Have fun.