Change Avast Pro to Secure Internet

On my PC I have Avast Secure Internet (Licence till March 2015).
On my Notebook I have Avast Pro (Licence ending Today)

What ist the best way (chepest way) to upgrade to Avast Secure Internet for both systems?

Any hint is appreciated

WalterVOFUY

Check the vendors websites.
There could be one that has a special deal for a license.