Download either of these files and extract in desktop. Copy everything in to your drive. If Windows, it is 465MB. Mac 181MB. Unlock tools are in the folders.
My Passport Drive Contents: Windows
http://download.wdc.com/smartware/WDSmartWare_PP4R2_1_4_1_2.zip
My Passport Drive Contents: Mac
http://download.wdc.com/smartware/WDSmartWare_Mac_Disk_Image_PP4R2_1_3_0_18.dmg