Relic Castle

I've seen differing tutorials, suggestions and methods for installing Elite Battle System (and similar additions to your game like Modular Menu). However every time I've tried I've come up short either because development was discontinued or my attempts to add it just doesn't work. My most recent attempt tried to use Elite Plugin Installer but that crashed my computer and then came up with script errors whenever I restarted it. What I'm asking is for someone to guide me through the process because I'll be honest I don't really know what I'm doing and I'm just getting confused. If I have to manually install it I'll do it, just guide me step-by-step. Thank you for your time and hopefully your help.