Combine 3 stores together as Multistore Prestashop

I have 3 different stores in prestashop and want to combine as multistore.

I am new to prestashop and searched regarding this. Can anyone suggest me how can i combine 3 websites as multistore in prestashop.

Thanks in advance.

As Julien said, it's not an easy task.

Due to the lack of information in your question I will suppose that all your shops are using the same Prestashop version and no core files got hacked.

You should first choose the website that will host the other two. The easiest way to do this is to choose the most complex of the three and adding the other two to it.

Then you should:

• Activate multistore on it and add two new stores.
• Import themes from the older stores.
• Import products and related informations (categories, features...) from the older stores.
• Install missing modules.
• Install missing overrides.
• Import users and related informations (addresses, orders, ...) from the older stores.

If you didn't did anything special on those stores, everything could (not should) be done painlessly. But export and import features on Prestashop are really capricious...