This one I always forget every now and then: I open up Virtualbox to update it and its extension pack, I have to do this. This time I’m bookmarking this in a post.

For those of us for whatever reason can’t just do the normal double click - install and needs to run the install in an system elavated command prompt.

It’s self explaintory below or refer to the reference documentation.

VBoxManage extpack install --replace "updated_Extension_Pack.vbox-extpack"

Reference at time of writing of this post is :
Oracle® VM VirtualBox User Manual for Release 6.0 - Section 7.41: VBoxManage extpack