I recently encountered some problems with my Dell XPS 13 running Ubuntu 17.10. I updated the linux kernel to the latest version. With the new kernel running, my wifi adapter wasn't working anymore. Also Virtualbox doesn't work anymore. I searched a lot on the internet but couldn't find any solution. I was told my only option would be to downgrade the kernel to the previous working version.
Now the problem with this is, I'll have to use GRUB. My laptop has been showing difficulties since some weeks, and one of them is that my laptop won't boot most of the times. The times it does boot, it goes straight to the disk encryption password prompt, meaning I can not boot from USB, enter bios or enter the GRUB.
Now my question is, is there any other way of downgrading the kernel without using GRUB? I have figured I might take out the SSD and try to fix it from another computer, but I don't have the necessary tools to open it up, and even if I did, I wouldn't know where to plug in a M.2 ssd.