Hello, For this Go to the Appearance > Editor > infoway-front.php and make changes as shown in image.
1. To edit 'Send Your Message' text, Go to the infowway-front.php file (Theme directory > functions directory> infowway-front.php file) present in your Theme directory and edit the text as shown in the image given below. Through this you can translate the 'Send Your Message' text. 2. You can change the text 'Your Message has been successfully submitted and mail sent' from "leads_class.php" file, You will get the file from your theme directory (Theme directory ->Functions Directory ->leads_form directory ->leads_class.php file), you can edit the text from there as shown in the image given below. Through this you can translate the 'Your Message has been successfully submitted and mail sent' text.