As you may see, domain name for new web store is different, which is why I’m afraid that Google will treat it like a completely new web store and thus that my ranking in search results will drastically degrade.
I was wondering how to make complete redirect from old to new store and tell Google to retain current website ranking? Do you perhaps have any other suggestions? Thanks!
Once you’ve taken care of Google with the change of address tool, your main consideration should be ensuring that human visitors are correctly redirected to the new site. If it works for them, it will work for search engines, too.
From htaccess of old domain do a 301 redirect. You can have full domain (all pages) redirect to new domain home.
But preferred way is to do 301 redirect to each individual page.(this sounds bit cumber-sum if you have say 100 + URLs but certainly better solution)
with this you will not loose your site ranking <snip>