What format do you want your drive in and what format is your disk currently? You can use diskpart or disk management on a windows PC, disk utility or terminal on a mac. You can use bash on a linux system or any of the countless third party disk utilities available online.
You may not necessarily need to format your disk depending on what system your moving it from and too. Create a backup of your old disk first using something like Acronis to an external HDD.
You should also run some pseudo-random data passes over your disk if your security conscious. (dependent on you) which is how i would wipe it.
If not that you could just click windows key/type 'cmd' (right click run as admin)/type 'diskpart' (press enter)/ in diskpart type 'rescan' (press enter), wait then type 'lis dis' (press enter) find your disk you want to wipe.. (be careful) type 'select disk x' (x=your disk number) (press enter) type 'clean' (press enter) type y (press enter)
that should wipe it, now you just have to initialize the disk, create a partition and format it in i.e NTFS or exFAT