Hi BanAnna42 ,
One way this could be done is by linking two different surveys together. Survey 1 would have the majority of the questions, while survey 2 would have the question where they enter their email (and any other personally identifiable information you want to collect to send them the instructions). Survey 1 would have an End of Survey element in the Survey Flow that redirects actually to survey 2. You can then set up the Action when they submit survey 2 that emails the instructions.
The Qualtrics Support pages have a use case that describes how to link surveys together. It's a bit more complicated than your scenario, but it might help illustrate how to connect your two surveys.

You could also just give them an option to download a pdf of the instructions.

I believe you can do based on an embedded data field that is not defined in the survey flow. That prevents it from being saved in the response data. The only question is if the temporary embedded data field stays around long enough to trigger the action.
Add your own html input field to capture email, then use JS to save it to an embedded data field. If the field is not empty send the email.

https://community.qualtrics.com/XMcommunity/discussion/comment/43117#Comment_43117I believe you can do based on an embedded data field that is not defined in the survey flow. That prevents it from being saved in the response data. 

https://community.qualtrics.com/XMcommunity/discussion/comment/43106#Comment_43106Thanks! I have come across this use case! However, I don't understand how this would enable me to not save the email addresses of the people I want to email the instructions to. As far as I understand, this would mainly have me save the email addresses in a separate survey's data, right?

https://community.qualtrics.com/XMcommunity/discussion/comment/43115#Comment_43115Yes, that's what I am doing already. I was just hoping to add an additional way for them to keep the instructions in case they open the survey on their phone. I am targeting a potentially less computer-literate population so I am trying to make this very fool-proof. Thank you anyway!

https://community.qualtrics.com/XMcommunity/discussion/comment/43123#Comment_43123That is correct that the email address would be saved, but it would be in a dataset that is separate from the main survey responses. As a result, the main survey responses would not be linked with their email addresses and would remain anonymous.