How to upgrade Storefront for Joomla 2.5 to Joomla 3 ?

Hi !
I have Storefront fot Joomla 2.5 running on a Joomla 2.5 website - Great
I need to upgrade to Joomla 3
What is the method to have Storefront working well ?
I tried to install Storefront for Joomla 3 without uninstalling the 2.5 Storefront version after I did the Joomla upgrade
but I have many errors (blank pages...)
Is there a tutorial somewhere ?
Thanks

Hi

No tutorial I'm afraid. From what I remember most of the problems are with plugins, so download rest_files plugin and un-install than install a jomla 3.4 version plugin You will find in this package. Of course, I'm assuming all modules are updated already.