LibreOffice 4.0 is a major release, and hence may not be available in Ubuntu 12.10 via Software Updater (reason already mentioned by @vasa1 in a comment to your question, I'd recommend to read this answer of the same thread).
But if you're still interested in installing LO 4.0 in your box, WebUp8's Guide should get that done (and I don't think process explained there is that complicated). ;-)
And if its still complex for you, let's make it easier FTW. Here you go.
If you're using any previous versions of LO4 (Beta, RC, etc.) Better you follow up the link I've provided above ('cause you're already brave then). If not, do as follows.
- Grab appropriate
.deb installer (technically, it'll be a
.tar archive) for your version of Ubuntu here.
- The one you downloaded is one giant TAR archive (~160+ MBs), and now real work starts.
- Go to your
home folder and create a new folder called
libreoffice and put that TAR file in here. Now open terminal using short-cut Ctrl+Alt+T and navigate to
libreoffice folder by running command
- Now extract the archive by running
tar xvf libreoffice_downloaded_file.tar (be sure to replace with actual file name you've downloaded.
- Once extraction is done, run following command to install
sudo dpkg -i *.deb. It'll ask for password and once installation is done, exit terminal and look for LibreOffice 4 apps in Unity Dash.