Hi,
I thinks that the best way is to start from scratch.
On the new install, install a fresh version of Hikashop, update HikaShop on your old version.
Then export the hikashop tables from the old database, and the users etc... tables.
Import them in the new site to get your customers, addresses, configurations back.
In the folder, get the content of the media/com_hikashop/ if you made overrides you can get them back from the folder "templates/your_old_template/com_hikashop" to put the content in the new website.
Doing this way allow you to keep the old version working, and if you are broking something in the new one, you can start again without losing any informations.