To save the index of the search engines all pages of your site you need to set up redirect pages to similar to the new domain. To do this, transfer the whole content to a new domain you must purchase and configure there DNS server. After delegation, you need to bind the new name of your site to the old site.
Make redicat. Locate the root directory of the site the file is called .htaccess and write it like this:Options +FollowSymLinksRewriteEngine onRewriteRule (.*) http://имя_нового_сайта.ru/$1 [R=301,L]After you complete this procedure, search engines and all users, passing on the links to the old url of your website will be automatically redirected to the new address.
For indexing by search engines Yandex and Google add the new domain to Google.Webmaster and Yandex.Webmaster. To implement more rapid re-indexing make search engines to see your site schema, and new and old addresses. On the main page to do so, place a link to it. The scheme is resource with old addresses allows you to refresh pages, which is configured to redirect virus. The new scheme will allow to index pages created after the change of the name of the resource.
Then make it so that the user, when passed through the old website address, got on the 404 page, which would indicate that the resource was renamed, and he now has a new address.
After all these operations you will just have to wait for the moment when search engines index the resource. If you have performed all the actions correctly, the main indicators of the site TIC and PR will not change. However, the domain change is a very serious step, so before you implement it, think carefully.