DJ88, if your stock servo's are on a circuit board then they are controled by a pot and it's not worth the trouble to try to hack it unless you have new servo's that are the same as the stock ones, in which case you can just solder them, however this is tricky and easy to mess up. converting the string controled planes can be done but you need all new components to do it, and it takes some work. There are a couple threads about converting aerobird and firebird that might help you