Use following code to remove "FROM" text product price.

Method:

1. Copy code to your functions.php.

/* Remove FROM text */
add_filter('woocommerce_variable_price_html', 'bas_variation_price', 10, 2);
function bas_variation_price($price,$product) {
 $price = '';
 if ($product->min_variation_price || $product->min_variation_price !== $product->max_variation_price){
  $price .= woocommerce_price($product->min_variation_price);
 }
 return $price;
}