[GTALUG] VirtualBox Guest Additions in Ubuntu VM doesn't work

[William Park]

Question for Ubuntu users...

VirtualBox Guest Additions installed by default on Ubuntu/Kubuntu VM is
5.0.18, ie.
    modinfo vboxsf
    
Now, when I try to upgrade to latest 5.1.8, the install script
(VBoxLinuxAdditions.run inside VBoxGuestAdditions.iso) finishes OK, but
the version is still 5.0.18.  Looking at kernel drivers, it seems that I
have 2 versions of drivers:
    kernel/ubuntu/vbox/...	--> from Ubuntu kernel
    misc/...			--> newly compiled

When I removed the default kernel drivers, then it uses the newly
compiled 5.1.8 drivers. (which is what I want)

What is Ubuntu-way of removing kernel drivers, or specifying which
driver should be loaded?
-- 
William