搭建博客出现 port 4000 has been used 如何解决？

手 jiàn 将 blog 文件夹删除，重新搭建提示 4000 端口被占用

FATAL Port 4000 has been used. Try other port instead.
FATAL Something's wrong. Maybe you can find the solution here: http://hexo.io/do
Error: listen EADDRINUSE 0.0.0.0:4000
    at Object.exports._errnoException (util.js:1026:11)
    at exports._exceptionWithHostPort (util.js:1049:20)

网上找到解决办法是在_config.yml 加上代码更改 hexo-server 运行时的端口号，例如 4001

server:
  port: 4001
  compress: true
  header: true

我其实心理上不愿意这样操作，想学习下如何清除之前的 4000 端口？（ Ps 非程序员）