I think I know how to, but I got denied access every time I tried to upload my logo into the 'images' folder. My ftp connection is fine since I did successfully upload the header image into the 'header' folder. For some reason the 'images' folder wouldn't let me. Is it locked by Wordpress? Please help!

Folders are not 'locked by WordPress' the server software sets the premissions. You sould check the folders 'permissions' (see Changing File Permissions)

Check the permissions for the 'header' folder and then for the 'images' folder and set the 'images' folder to the same as the 'header' folder

Got it. Thank you!