How to install Libre Office without GUI

The Libreoffice packages depend on libreoffice-core, and libreoffice-core alone drags in 90+ packages:

# apt-get install libreoffice-core --no-install-recommends
Reading package lists... Done
Building dependency tree       
Reading state information... Done    
The following extra packages will be installed:
  fontconfig fontconfig-config fonts-dejavu-core fonts-opensymbol
... snip ...
The following NEW packages will be installed:
  fontconfig fontconfig-config fonts-dejavu-core fonts-opensymbol
  gconf-service gconf-service-backend gconf2-common libatk1.0-0 libatk1.0-data
  libavahi-client3 libavahi-common-data libavahi-common3
  libboost-date-time1.54.0 libcairo2 libclucene-contribs1 libclucene-core1
  libcmis-0.4-4 libcolamd2.8.0 libcups2 libdatrie1 libexttextcat-2.0-0
  libexttextcat-data libfontconfig1 libgconf-2-4 libgdk-pixbuf2.0-0
  libgdk-pixbuf2.0-common libgl1-mesa-glx libglapi-mesa libglu1-mesa
  libgraphite2-3 libgtk2.0-0 libgtk2.0-common libharfbuzz-icu0 libharfbuzz0b
  libhunspell-1.3-0 libhyphen0 libice6 libicu52 libjasper1 libjbig0
  libjpeg-turbo8 libjpeg8 liblangtag-common liblangtag1 liblcms2-2 libltdl7
  libmhash2 libmythes-1.2-0 libneon27-gnutls libnspr4 libnss3 libnss3-nssdb
  libpango-1.0-0 libpangocairo-1.0-0 libpangoft2-1.0-0 libpixman-1-0
  libraptor2-0 librasqal3 librdf0 libreoffice-common libreoffice-core
  libreoffice-style-galaxy libsm6 libthai-data libthai0 libtiff5 libx11-xcb1
  libxcb-dri2-0 libxcb-dri3-0 libxcb-glx0 libxcb-present0 libxcb-render0
  libxcb-shm0 libxcb-sync1 libxcomposite1 libxcursor1 libxdamage1 libxfixes3
  libxi6 libxinerama1 libxrandr2 libxrender1 libxshmfence1 libxslt1.1 libxt6
  libxxf86vm1 libyajl2 lp-solve uno-libs3 ure x11-common
0 upgraded, 91 newly installed, 0 to remove and 0 not upgraded.
Need to get 68.6 MB of archives.
After this operation, 271 MB of additional disk space will be used.
Do you want to continue? [Y/n] 

So you can't get away with installing any fewer. The libreoffice package brings in about 30 more packages. However, if you don't install the integration packages (libreoffice-gnome, libreoffice-kde), you wouldn't bring in the GNOME/KDE components. The libreoffice doesn't depend on these integration packages, so you should be OK with installing just libreoffice:

apt-get install libreoffice --no-install-recommends

The package libreoffice doesn't depend on Gnome, KDE or Xorg (See Ubuntu Packages).

To keep the installation minimal you can install it with no recommended stuff:

apt-get --no-install-recommends install libreoffice