Extract the .SQL file from your backup. After you've extracted it, upload it in public_html,

Download: Bigdump

Open the bigdump.php file in Notepad++ or any other text editor you are using, change these lines:

PHP Code: 
$db_server   'localhost';
$db_name     '';
$db_username '';
$db_password ''
If you get error:
At this place the current query includes more than 300 dump lines. That can happen if your dump file was created by some tool which doesn’t place a semicolon followed by a linebreak at the end of each query, or if your dump contains extended inserts. Please read the BigDump FAQs for more infos.
Change this:
PHP Code: 
define ('MAX_QUERY_LINES',300); 
Put it like 600 or 1000.

After you've edited the file and uploaded the bigdump.php in same folder with .sql file, database importing will start. After you've finished importing delete the .sql file and bigdump.php from your server.