How do I start dialog with loan company about possible deed in lieu of foreclosure?

i am 58 years old, my husband is 56. we purchased 1/2 duplex at the coast several years ago. we have had it on the market for almost three years and have not had a single offer. we had the place appraised in september 2008 and the appraisal was $324,000. our present asking price is $279,900 and we are offering $5,000 extra to selling agent and $5,000 on closing cost and still no offers. at the time we purchased the duplex, we had several years payments in savings and our primary home was paid for. since we purchased the duplex, we ended up with no vacation rentals for the first two years of ownership and only a few rentals the next year, rentals continue to be spread thin, we have refinanced our primary home and used the proceeds to keep up the mortgage payments on the duplex and to pay the extremely high cost of insurance, especially flood insurance, taxes and constant maintenance. we have not accumulated credit card debt of approximately $16,000. my husband is suppose to retire soon. we are now two months behind on the duplex payments (june and july) with wells fargo. my daughter suggested we try for a deed in lieu of foreclosure. i don't know what to do and have become quite desperate. we can maintain the payments on our primary residence and the credit cards and keep up our monthly bills but we just do not have the funds to keep making payments on the duplex. help!! how do i go about getting this done with wells fargo? we would be loosing all that we have invested and all we have borrowed on our primary home and our credit will be destroyed but at this point, our credit is probably destroyed anyway since everything is getting paid late. desperately need advice.