The short answer is no, you cannot.
It is possible to replace them, the difficulty becomes the cost and labor.
LCD panel replacement is virtually never feasible as it can take several hours of skilled tech labor on each. The cost of the panel is 80-90% of the value of the tv, so it ends up costing far more than the tv is worth.
The bigger issue in this case though is the brand. These RCA tvs are some of the lowest quality sets on the market (the reason they were probably being returned) and are very poorly supported. They don't actually make them, they are made by any number of random 3rd party chinese companies and badged with the rca name. They do not make any parts available for them, it would be impossible to find replacement panels for them.
If you want to get some value out of the tvs, you'd be best off opening them up and stripping out the power supply, tcon, and main boards. You could sell them individually (ebay) or sell the lot of them to a resale company like shopjimmy.com.
If you have any other questions, just let me know. Otherwise, please take a moment to rate my service as this is the only way I am credited for my time. Hopefully I have earned 5 Stars but if not please let me know what I can do to ensure you are satisfied. I also invite you to contact me directly with any future support needs at http://bit.ly/1QwLxGh and ask for Nathan.
Thank you, ***** ***** a nice day,