However, when booted into Ubuntu you can mount the Windows partition
and have read/write access to it so all your documents / pictures /
music etc will be available for use in Ubuntu. There's no need to copy
everything from one to the other

I understand the above but not how to execute it. Can someone elaborate in
more detail? I've been in, I think it's, Libre Word or Write but can't find
my MS Words docs from there.