For your entire store
To change the default theme that users will see when they enter your store, do the following:
1. Open Store Settings
2. Change Theme
Select the theme you want your store to have using the "Default Theme" field in the General Settings section.
3. Click
For a single user
By default, a user can change the theme for themselves, without effecting the default theme for your store.
1. Login on Storefront
2. Change Theme
Change the Theme field in "Account Options". The page will refresh with the new theme.
Note: If you are logged in as admin and you are in the admin interface, you can also change the theme for your account using this menu option: