New theme while keeping everything else

[Dl1409]

Hi,

 

Am new to prestashop and researching a project. The Client is happy with prestashop, all running well for them with integrated stock system, accounting package, good seo and large product database. All this is to remain in tact, but wants to improve ui and address ux issues.
 

Rethemeing is the option I am looking at, but unsure technically how changing theme behaves with minimal impact on backend, want to avoid rebuilt if necessary. But will quote for rebuild if retheme can causes issues. 
 

Thanks, any help appreciated. 

[PrestaHeroes USA]

create a dev copy apply theme to dev, test

when ready back up production

apply new theme to production