The internal HD is NOT in NTFS format, it is a proprietary encrypted Sony format. You can do 2 things:
1. Plug in a external USB Drive and copy the individual items you want to save like Game Saves, Media, Game Backups (if you are using a backup manager), etc. Note that you cannot backup trophies without syncing them to PSN.
2. Plug in a external USB drive and use the Backup HD utility in the Settings category to make a copy of your drive. Install your new HD, then use the Restore HD utility in settings. This will take longer but will make a 1:1 copy.