Can't remove "Install macOS High Sierra.app"

I had to make a bootable macOS High siera install, everyhing went well and it worked. I'm trying to remove the app that I used to install it and trash won't let me. Everytime I try I get an The operation can’t be completed because the item “Install macOS High Sierra.app” is in use. error. I tried to circumvent this by option+click and selecting "Delete immediately" but that just gives me an “InstallESD.dmg” can’t be modified or deleted because it’s required by macOS. error. Any help for getting this thing off my computer will be greatly appreciated.