Removing previous version(If you have)

sudo apt-get remove skype skype-bin:i386 skype:i386
sudo apt-get install sni-qt:i386

Preparing to Installing Skype:

Users of 64-bit should enable MultiArch if it isn't already enabled by running the command:

sudo dpkg --add-architecture i386

Now,

Open Software& Update --> Other software tab then enable Canonical Partner repository.

Then close --> reload

Install skype

Now open terminal and run

sudo apt-get update
sudo apt-get install skype

Reference here

Removing previous version(If you have)

sudo apt-get remove skype skype-bin:i386 skype:i386
sudo apt-get install sni-qt:i386

Clear the old Skype folder before installing latest version.

rm -rf ~/.Skype

Preparing to Installing Skype:

Users of 64-bit should enable MultiArch if it isn't already enabled by running the command:

sudo dpkg --add-architecture i386

Update repositories and "updates" list:

sudo apt-get update

Now,

Open Software& Update --> Other software tab then enable Canonical Partner repository.

Then close --> reload

Install skype

Now open terminal and run

sudo apt-get update
sudo apt-get install skype

Reference here

1. Install Skype from Canonical Partner repository

   Open Software& Update --> Other software tab then

   enable Canonical Partner repository.

   

Then close --> reload

Now open terminal and run

    sudo apt-get install skype

Removing previous version(If you have)

sudo apt-get remove skype skype-bin:i386 skype:i386
sudo apt-get install sni-qt:i386

Preparing to Installing Skype:

Users of 64-bit should enable MultiArch if it isn't already enabled by running the command:

sudo dpkg --add-architecture i386

Now,

Open Software& Update --> Other software tab then enable Canonical Partner repository.

Then close --> reload

Install skype

Now open terminal and run

sudo apt-get update
sudo apt-get install skype

Reference here