how to properly override the function?

[feelexit]

I am working on my first theme. in the tpl_product_info_display.php page, it uses " zen_get_products_display_price((int)$_GET['products_id'])" to display the price.
this function added "<br/>" tag
$35.99 $30.00
Save: 17% off

I want this to be one line. ($35.99 $30.00, Save: 17% off).

I try to add "my-style" folder to "includes/functions", then override the function. but its not working. I prefer not to change the function file directly, please show me the proper way to modify the functions.

[DrByte]

Due to the way functions work, there are no overrides for function files.