The preference dialog can be started by selecting the File and then the Preferences menu item.
The dialog is used by selecting one of the categories in the top left column of options and then changing the settings for that option. The categories are presented as a list; each can be selected in turn by placing the mouse pointer over the desired element and clicking with the primary mouse button.
Certain elements, such as the Font preference, have a small triangle in front of their name. Clicking on this triangle will open a sub-element line which allows the sub-element to be selected and have its options altered.