No problem, happy to answer! I usually resize in Photoshop, but it can be done in CSP too. In CSP, you go to File -> Export (Single Layer) -> PNG (though in some cases such as very detailed full color illustrations, JPG may be better). Use the save dialog box and then hit save. This will bring up export settings. Under "output size", there are three different options for scaling. You can scale by percentage, size, or resolution. There are various other options to choose from as well.
In Photoshop, I use Image -> Image Size. You can use the drop down box to choose either pixels or percentage. Personally for my comic pages, I chose 12.5%. When you resize down ALWAYS save a copy so you have one at original size and one at the small size.
Then I save using File -> Save For Web (CS6 or earlier) for Photoshop CC it's under File -> Export -> Save for Web. Then you can have some control over the settings and can resize from there as well.