To edit Grub2 during the boot process try the following:

为了在启动时，编辑GRUB2，可以尝试下面的步骤

1. Immediately after the BIOS splash screen during boot, press and hold the SHIFT button. This will display you grub containing a list of kernels and recovery options
   在启动过程中出现 BIOS 启动画面后，立即按住SHIFT按键。
   这将显示包含内核和恢复选项列表的grub。
   

2. Press e to edit the first kernel displayed
   按e编辑显示的第一个内核
   

3. Find the line ending with quiet splash. Add your boot option before these key words - i.e. so the line looks like [...] nomodeset quiet splash
   找到以 quiet splash 结尾的行。 在这些关键字之前添加您的引导选项 - 即该行看起来像 [...] nomodeset quiet splash

4. Press CTRL + X to boot
   按CTRL+X启动

参考文章

https://askubuntu.com/questions/38780/how-do-i-set-nomodeset-after-ive-already-installed-ubuntu
https://www.dell.com/support/kbdoc/zh-cn/000123893/手动-nomodeset-内核引导-行选项-用于-linux-引导