Get Firefox, make sure you install the DOM inspector. There are plenty of
other tutorials out there, but it basically works like this.
- Launch the DOM Inspector
- click the mouse cursor icon in the top left corner
- click the element you want to change on the page
- look at the class or id names of now selected element in the DOM insepector
- modify the /components/com_rsgallery2/rsgallery.css accordingly