Can't hack on crafting dead

Hello, i'm a complete noob at hacking and help with my question would be much appreciated. So, there is this modpack called crafting dead and for someone reason i can't install a simple hack like "Radarbro" because when i try to edit the jar or anything along the lines of that, when it launches it goes to a menu that says something along the lines of "Do not edit this jar" and from there i cant click on anything. When i just place it in the mods folder it just white screens when launching and i know for a fact it works that way because i tested it with the same mods but took out the crafting dead mod.

Look up how to install hacked clients. You'll find that editing a jar file is not all you need in order to edit minecraft. It requires an extra step.