HAMMER said:

HELLO. I WANT TO UPGRADE MY TOWER  BY TAKING ADVANTAGE OF THE 25% DISCOUNT AND I CANT FIGURE OUT HOW?  I HAVE TO DEMOLISH IT AND REBUILT IT INTO A HIGHER LEVEL  FOR UTILIZING THE DISCOUNT ?

THANKS

In fact friend the discount is not to improve but to create a new.

En efecto amigo el descuento no es para mejorar sino para crear una nueva

Paulinho said:

wait to sign towers levels 5 and after that go   and buy towers to levels 10   , it's isn't worth it another way ..if you already bought some towers demolish them when you sign    towers level 5 achievement  and after that buy level 10 towers       ( you should have also  a lot of drachmas in youre account for this because plarium are greedy  :)) 

Thanks for your recommendations to other players.