woocommerce edit $price get_price_html

I am new to Wordpress Woocommerce.

I am trying to edit the displayed price.

1. Add text before and after the price, if there is a price value.

Result: HKD Listed Price: $218,000.00 Contact us for special price.

2. Display text, if the price value is empty.
   
   Result: Contact us for price.
   
   
   

I looked into the price.php and find get_price_html(); ?>

And have no idea how to find and edit the source.

Thanks.