How do I disable my iPhone 7 on another iphone

I can't imagine why you would want to DISABLE your phone. But if your phone is actually disabled, you cannot fix it using another iPhone. The ONLY way to get back into a disabled iPhone is to erase it using your home computer with iTunes (Windows) or Finder (Mac). See the directions in this link and follow them EXACTLY --> If you forgot the passcode on your iPhone, or your iPhone is disabled - Apple Support