Hi Chris! My name is ***** ***** it is my pleasure to assist you today.
Cropping someone from a photo can be done a few different ways, but you'll need to determine the best way to go about it based on the content and layout of the photo in question. Certainly, the first step will be to make sure you have an image editor installed that lets you perform these sort of alterations. One of the best -- which is not only an awesome photo edit but is also FREE -- is GIMP. You can download it from gimp.org. Adobe's Photoshop is the de facto standard in image editing, but is not free. You can purchase it from Adobe directly for $19.99/month.
As far as editing the photo itself: if the subject you're wishing to crop is near an edge of the photo, you may find it preferable to crop the entire image down enough to remove the person from being visible. To do that, you'd choose the "crop" tool from your image editor of choice, draw a box around the part of the image you want to keep, and press your ENTER key. Voila!...your modified image discards the area outside of the box you drew, and the undesirable subject is gone.
Another option is to manually "erase" the person from the image; using Photoshop, for instance, this can be done by using the "freeform selection" tool to draw a line around the person you wish to remove; then click the DELETE button on your keyboard, and choose the option to use "Content Aware Fill" for the background (that will attempt to fill in the section of the image you deleted with a background that matches the rest of the picture; in a best-case scenario, this results in a nearly-perfect edit in which you would never be able to tell the undesirable person was ever in the photo).
Hope that helps give you some guidance! Here is some addition information about the process that you might find helpful: http://planetphotoshop.com/removing-objects-with-content-aware-fill-and-patch-in-photoshop-cc.html