How do you change the dpi setting in a digital image using photoshop?

I'm trying to meet the format requirements for the submission of a head-shot. All they want is that the image be 35% of its original size and 100 dpi (whatever that means)How do you change the dpi setting in a digital image using photoshop?
Before you do anything, open the file and name it something else. Otherwise you run the risk of overwriting your high resolution file and losing it forever.



Now .. in Photoshop, with the new file opened, do this: Image %26gt; Image size. First change the resolution to 100, then calculate what 35% of the pixel width or height is and put that figure in. (if you do this the other way, you will see your image size change when you change the resolution)



That will do it.



NOTE: When they said 35% of its original size, did they mean its dimentions from say 4x6 inches to about 2.5x4 inches? Or did they mean, from 100kb to 65KB? You may want to clearify that before you spend too much time on the image(s)How do you change the dpi setting in a digital image using photoshop?
Go up into image and either image size or canvas size.
i've seen this done, and i've even done it a time or two, there is a dialogue box that drops when something in image or windows is choosen but i have cottage cheese for brains today, so i gave you a star in hopes that someone that knows will answer you and not be a troll and not give my answer the boot.
look on the top tool bar for image

go to image size change the dpi to 100 and the size of the height or width to the size you want and click ok

go to file and save but rename the file or it will save over the old one

I hope this helps