To upgrade to linux 5.5.0 kernel, you can perform the following steps:
1st) Download the following files to an empty folder (for 64bit & generic kernel):
wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.5/linux-headers-5.5.0-050500_5.5.0-050500.202001262030_all.deb wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.5/linux-headers-5.5.0-050500-generic_5.5.0-050500.202001262030_amd64.deb wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.5/linux-image-unsigned-5.5.0-050500-generic_5.5.0-050500.202001262030_amd64.deb wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.5/linux-modules-5.5.0-050500-generic_5.5.0-050500.202001262030_amd64.deb
2nd) execute the command:
sudo dpkg -i *.deb
3rd) In the end, after the installation has taken place, all you have to do is restart the server
reboot
After restart you can check which version of linux is active
uname -r