If you have only had them listed on TUG, I think that's part of the problem. In this market, you need to advertise widely for the most traffic. Orlando has far more supply than demand, so you need to be very competitive to rent.
Other possible issues:
-Week 39 has low demand (school holidays rent best.)
-Priced too high - you have lots of competition - you need to be near the bottom of the Comps.
I cannot use them and want to exchange to another property that I can rent out with better sucess than I am currently getting.
You cannot exchange a week through an exchange company and then rent it - the exchange companies do not permit it. If you mean you want to reserve a different week at your home resort to rent, you can do that.
Right now, a lot of people are trying to rent their timeshares, so you want to price your week competitively, market it well, and make sure you have a lot of traffic - because you have a lot of competition. I personally use these cheap or free websites to post my Ads:
TUG Timeshare Marketplace -
http://tug2.com/timesharemarketplace/
1 year Membership - $15
Ads - free up to 25
www.craigslist.org (free)
www.redweek.com
Membership - $14.99 for 12 months
Timeshare Rental Ads - $24.99/ea for 6 Months
Timeshare Resale Ads - $59.99/ea for 12 Months
www.myresortnetwork.com
Membership - free
Timeshare Rental Ads - $19.95 ($24.95 - floating weeks)
Timeshare Resale Ads - $34.95
There is also a list of resale websites at the top of the Buying, Selling, Renting, board that you may want to take a look at.
Some people don't like Craigslist, because you get a lot of scammers who respond, but they are painfully obvious, and I just ignore them. Another tool I use to eliminate the scammers is that I only accept payment by Paypal which requires a verified bank account or credit card to be registered.
On Craigslist, you need to create a Craigslist Acct., create 3 different Ads with different titles and wording, and rotate them every 3 days. You don't have to rewrite the Ads - if you create an Acct. they will be saved in your Acct. and you can just use the "renew" function, to renew the oldest Ad every 3 days which will bring it to the top of the listings.