How do I update the redhat kernel?

vaquitasos

$ sudo dnf update kernel
Red Hat Update Infrastructure 3 Client Configur 2.3 kB/s | 2.6 kB     00:01
Red Hat Enterprise Linux 8 for x86_64 - AppStre  38 MB/s |  14 MB     00:00
Red Hat Enterprise Linux 8 for x86_64 - BaseOS   39 MB/s |  14 MB     00:00
Dependencies resolved.
================================================================================
 Package        Arch   Version               Repository                    Size
================================================================================
Installing:
 kernel         x86_64 4.18.0-147.5.1.el8_1  rhui-rhel-8-baseos-rhui-rpms 1.5 M
Installing dependencies:
 linux-firmware noarch 20190516-94.git711d3297.el8
                                             rhui-rhel-8-baseos-rhui-rpms  66 M
 kernel-core    x86_64 4.18.0-147.5.1.el8_1  rhui-rhel-8-baseos-rhui-rpms  25 M
 kernel-modules x86_64 4.18.0-147.5.1.el8_1  rhui-rhel-8-baseos-rhui-rpms  22 M

Transaction Summary
================================================================================
Install  4 Packages

Total download size: 114 M
Installed size: 406 M
Is this ok [y/N]: y
...
...
...
Installed:
  kernel-4.18.0-147.5.1.el8_1.x86_64
  linux-firmware-20190516-94.git711d3297.el8.noarch
  kernel-core-4.18.0-147.5.1.el8_1.x86_64
  kernel-modules-4.18.0-147.5.1.el8_1.x86_64

This will check what you are running and what is installed.

# dnf check-update kernel
Last metadata expiration check: 0:17:05 ago on Mon 02 Mar 2020 02:22:34 PM UTC.
Security: kernel-core-4.18.0-147.5.1.el8_1.x86_64 is an installed security update
Security: kernel-core-4.18.0-80.4.2.el8_0.x86_64 is the currently running version

On the next reboot you can run the latest kernel running.