In File Manager, click the menu in the top right of the screen and choose "Unlock full access". This should ask for your passcode/pin.
Once unlocked swipe up from the bottom to reveal "Places" and you should be able to navigate to the SD Card, which may have an obscure volume label as mine does.
Easiest way I found so far is to just download the armhf build of git from launchpad, extract it on my desktop and copy the contents to my phone. Then I can just run the git binary from where I have it copied to.
The latest armhf builds for git can be found here:
https://launchpad.net/ubuntu/utopic/armhf/git/
Download the deb of one of the builds and extract it (either with file-roller or with dpkg -x). After you extracted the deb, you'll have, among others, a usr/ dir which should contain everything you need to run git.
Upload that dir to your phone, so that its in your home, then just run
/home/phablet/usr/bin/git
and it should work. It'll complain about not finding templates when you do git init, but you can run it with
env GIT_TEMPLATE_DIR=/home/phablet/usr/share/git-core/templates /home/phablet/usr/bin/git init
to fix that problem.
If you don't want to type the full path every time you want to run git, you can set an alias in your .bashrc:
alias git=/home/phablet/usr/bin/git
Best Answer
A comment before recommended linking your SDCard from your home directory. This is how it goes.
ls /media/phablet/
. In my caseAC5D-91D7
AC5D-91D7
with the output of the command in step 2:ln -s /media/phablet/AC5D-91D7 SDCard
Now you can simply click on the SDCard folder in the File Manager App to see the contents of your SDCard.
Additional:
In case you want to keep your files on your SDCard rather than the internal storage you may consider (example for Music):
Your Music Folder is now located on the SDCard.