Implement Google Surveys Javascript to specific page of Wordpress Site

Hello, I have a wordpress run website that offers free audio downloads to visitors. Currently the visitors add free audios to their cart and then go through a checkout process via easy digital downloads. I would like to have it so that my google opinion survey loads on the "checkout - transaction complete" page where the visitors download their audios. Requiring the visitors to complete the survey before downloading the audios. I believe this should be a fairly simple project for someone who understands Javascript and wordpress better then myself, I would really prefer if someone could walk me through how to add this code myself rather then letting anyone log into my website and just do it themselves. If you convince me you can help me achieve this and implement the java myself by walking me through how to do it then you will be selected. Use subject teach java in your proposal so I know you have read through this fully and know what I am looking for. I look forward to working with you.