This Guide advisable for most large files.
Read carefully and do the Steps.
Step 1: Upload your backup SQL and rename it what your current DB Name. Example: ragnarok010125.sql
Step 2: Login your root Access in WINSCP and upload it directly on root folder.
Step 3: go to your current PhpMyAdmin Database and Drop All table in your current DB name to make sure its clean DB no other Table.
Step 4: After you upload the backup SQL. login on Putty SSH using root access and fillUP the following Code.
DB_USER="YOUR DB USER"
DB_NAME="YOUR DB NAME"
DB_PASS="YOUR DB PASS"
mysql -u $DB_USER -p$DB_PASS $DB_NAME < $DB_NAME.sql
Step 5: once you fill up this script. Copy Paste it on Putty SSH and then thats it wait for a minutes sometimes it take time to load again if your Backup is very large.
That's All I hope you Read and you understand how it works.