Install a Prestashop Theme and Modules

Hello, I recently bought this Prestashop theme (warehouse-responsive-prestashop-16-theme) and i want to install on my old website. My Prestashop is 1.6.0.9 version. When i try to install normally with upload from Presta Admin i just see the percent bar growing until 100% and then nothing happened. I have uploaded on ftp and try to install in that way but i get the message This theme is already on your server. The task i hope is clear, i need to install this theme and his modules. Please don't apply if you are not a Prestashop expert. At my level i have checked a lot of web solutions and i haven't solved this. Need something that know better Prestashop. For an expert it will take few mins to solve this. Thanks.