Extract the archive anywhere, then use any IPS-compatible patching tool to apply the patch file "halloweenfinal108.ips" to an original EarthBound ROM (regular 3MB ROM, NOT a pre-expanded one!)

Tools you can use for this include: Floating IPS, Lunar IPS (Toby's original recommendation), EarthBound Patcher, Coilsnake, Rompatcher.js.