Thumbnail Size

Hi there.

I am using design 1 and wanted to make the images larger than 100×100.

I edited the design template file to make it 300×300 (see below) which worked but now I can’t update the plugin in the future without fixing it every time.

 <div class="featured-content-image <?php echo $imagestyle; ?>"> 
						<?php if($sliderurl != '') { ?>
						<a href="<?php echo $sliderurl; ?>" > 	<?php if($wpfcasIcon != '') { echo '<i style="color:'.$faIconcolor.'" class="'.$wpfcasIcon.'"></i>'; } else { the_post_thumbnail(array(300,300)); } ?>		</a>
						<?php } else { ?>
						<?php if($wpfcasIcon != '') { echo '<i style="color:'.$faIconcolor.'" class="'.$wpfcasIcon.'"></i>'; } else { the_post_thumbnail(array(300,300)); } ?>	
						<?php } ?>
					</div>

Is there another option for me to change this size? If not that’s okay too but I thought I would ask.

Thank you