Hi Barry,
You certainly can!
Please review our Themer’s Guide first of all as it provides a good explanation of how template overrides work. In essence, though, you would copy this file:
plugins/the-events-calendar/src/views/modules/bar.php
Place the copy in your theme, like this:
themes/YOUR_THEME/tribe-events/modules/bar.php
Then locate this line:
<input class="tribe-events-button tribe-no-param" type="submit" name="submit-bar" value="<?php echo esc_attr( sprintf( __( 'Find %s', 'tribe-events-calendar' ), tribe_get_event_label_plural() ) ); ?>" />
Simply change it to:
<input class="tribe-events-button tribe-no-param" type="submit" name="submit-bar" value="Click to Search" />
Does that help?