Override function

Here is the code for overriding price of product in cart

add_action( 'woocommerce_before_calculate_totals', 'add_custom_price' );

function add_custom_price( $cart_object ) {
    $custom_price = 10; // This will be your custome price  
    foreach ( $cart_object->cart_contents as $key => $value ) {
        $value['data']->price = $custom_price;
    }
}