First you have to open the pic up using the "Paint" program, you can not shrink a pic from a web site directly. After you have it on "Paint", go to the "Image" tab on the tool bar. Then goto "Stretch/Skew", and you can change the horizontal and vertical size from there. After that, save the newly sized picture and then up ;oad it to a web site.
If you have any more questions feel free to email me
Sgtar15