First you need to have J.A.C.K editor installed (You probably already do if you're reading this guide).
Then you need to go to this website [forums.svencoop.com] and download the file at the bottom of the post. (Highlighted in the photo)










Then open the zip file you just downloaded and copy the tools folder into your Half-Life folder. (Forget about those other two).

First open J.A.C.K then press tools and then Options in the upper left corner.








Then press "Add..." under the "Game" tab.





















Then find zhlt.fgd in the tools folder you placed in your Half-Life folder.














After that, go to the "Textures" tab, press "Add Files..." and find zhlt.wad in the tools folder.










Create a new map, select Half-Life and you're done! Thanks for checking out my guide. If you have any problems just message me. You can also join my lonely mapping group.