Would like an example letter of surrender of mobile home and how to ask for short sale

Contact your lender to see what the best action may be.

Surrender goes by state. Google 'surrender your state' or tell us, and we will.
Here's an example of what an Affidavit needs in North Carolina:
http://www.ncga.state.nc.us/enactedlegislation/statutes/pdf/bysection/chapter_20/gs_20-109.2.pdf

But why don't you tell us all the story behind this? Maybe we can help with a better option. I'm not sure the lender has your best interests in mind. The clerk at your local tax or deed office might have suggestions too, and can go over your papers, what you owe, and delinquent taxes, if any.
Start with what it says in general on your title about liens, and what type of 'property' your home is.

First you can not just surrender, if the lender does not approve it, So you will need to discuss this with the lender and the lender would supply you with the forms if and when they approve it.

The same works for a short sale, you have to submit a request in writing, normally on the forms they supply with the buyers information and a firm offer from the buyer for a short sale.
If it is approved, then the sale will be arranged