If you are reinstalling first run the commands,
rm -rf /usr/local/texlive/2015
rm -rf ~/.texlive2015
then,
Download the .tar.gz
open terminal and run following commands,
cd ~/Downloads
wget http://mirror.ctan.org/systems/texlive/tlnet/install-tl-unx.tar.gz
tar -xf install-tl-unx.tar.gz
Currently we have version 20150927, therefore
cd install-tl-20150927
and install via
sudo ./install-tl
You wil see something like this
======================> TeX Live installation procedure <=====================
======> Letters/digits in <angle brackets> indicate <=======
======> menu items for commands or options <=======
Detected platform: GNU/Linux on Intel x86
<B> binary platforms: 1 out of 19
<S> set installation scheme (scheme-full)
<C> customizing installation collections
47 collections out of 48, disk space required: 4038 MB
<D> directories:
TEXDIR (the main TeX directory):
!! default location: /usr/local/texlive/2015
!! is not writable or not allowed, please select a different one!
TEXMFLOCAL (directory for site-wide local files):
/usr/local/texlive/texmf-local
TEXMFSYSVAR (directory for variable and automatically generated data):
/usr/local/texlive/2015/texmf-var
TEXMFSYSCONFIG (directory for local config):
/usr/local/texlive/2015/texmf-config
TEXMFVAR (personal directory for variable and automatically generated data):
~/.texlive2015/texmf-var
TEXMFCONFIG (personal directory for local config):
~/.texlive2015/texmf-config
TEXMFHOME (directory for user-specific files):
~/texmf
<O> options:
[ ] use letter size instead of A4 by default
[X] allow execution of restricted list of programs via \write18
[X] create all format files
[X] install macro/font doc tree
[X] install macro/font source tree
[ ] create symlinks to standard directories
<V> set up for portable installation
Actions:
<I> start installation to hard disk
<H> help
<Q> quit
Enter command:
make your changes and type I to install.