Step-by-step – Deepin Linux 15 GRUB Change Default OS Guide

Installing

2. 2. Installing GRUB Customizer

   Then to Install GRUB Customizer in Deepin
   Simply run:

   sudo apt install grub-customizer

   Authenticate with the User’s Admin Pass.
   If Got “User is Not in Sudoers file” then see: How to Enable sudo.