if you know how to put it in which is pretty easy, you don't need instructions, just the hard drive.
* set the jumpers
* put in the IDE and power cables
* screw the drive into a 3 1/2" bay
yep, totally agree with apokalipse. yes you did buy the OEM version, check the price you paid for the hard disk and the price of the retail box version. the only difference is you get no fancy packaging and pay less.