Question

How to change the size of my document in cs6?

Answer 1

When you're saving your image, it will ask you what quality of the image you want to use and it will show you that you're using a larger or smaller filesize depending on the quality of the image your saving.

<TIP>  Make a duplicate layer before saving the image and uncheck the original. Always save the CS6 file too to re-edit later if need be. But that way you will have the file size you want and the original image is preserved