Can you sell it? Obviously a cash sale would be best but mobile/manufactured homes sell a lot quicker if you're able to offer seller financing. Because there's a mortgage on it, you can't do it as cleanly, but it could be structured as a contract for deed (or, in this case, probably a contract for title). And you can get more money because people typically look at monthly payments, not the total purchase price. So--just making these numbers up--let's say you owe $20,000. You could try selling it for $20,000. Or offer it on terms: $3,000 down and $300 a month for 7 years. (That's charging 12% interest.)
Or find an investor to pay all cash, if you don't owe much. Let's say your double-wide typically would sell for $20,000. If you owed, say, $7,000, sell it to an investor for $7,000 cash. He's put in a few thousand dollars and sell it on terms. For instance, he might price it as: $3,000 down and $300 a month (same numbers as above). However, because his investment was only $7,000, his return on investment would be around 32%. That's enough to get the investor interested in buying it.
Hope that helps.