1. Disable System SIP

https://zhuanlan.zhihu.com/p/343151907

Before executing the command, you need to disable SIP (System Integrity Protection). The specific steps are: Enter Recovery Mode (hold Command+R during startup), open the system terminal in the upper right corner, and enter the csrutil disable (disable) command. After enabling HiDPI, you can use the csrutil enable (enable) command again to re-enable it. For more details, refer to »传送门

2. Enable HiDPI

After disabling SIP and restarting, execute the following command in the terminal:

bash -c "$(curl -fsSL https://raw.githubusercontent.com/xzhih/one-key-hidpi/master/hidpi.sh)"

Simply follow the prompts from the script. For specific operations, please refer to the developer’s documentation. »传送门

3. Install RDM

• RDM download address http://avi.alkalay.net/software/RDM/RDM-2.2.dmg

This site also provides RDM backup download