how to install update awocoupon pro ?

I have 1.2.3 version and I want to update to the 1.3.2
When I try to install it, it says I have already installed awocoupon pro.

Thanks seyi !

I have now the following bug in the admin side, since I tried to update by using the Install/Uninstall menu !

Warning: Invalid argument supplied for foreach() in /homez.383/pourmonm/www/administrator/components/com_awocoupon/models/coupons.php on line 57

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /homez.383/pourmonm/www/libraries/joomla/database/database/mysql.php on line 342

Please help

it looks like the files got updated but the database did not. I will pm you some sql statements to run on your db and hopefully that will fix everything.