With learning and practice anythng is possible.
Heck, you could even do your kids teeth with the proper tools and training.
If you couldn't do a simple RCA connector eith two leads, how do you think you'll do with an "S" connector with five?
Soldering ain't quite that difficult but don't expect to just pick up a gun and some solder and have great results. It is a learned skill and takes practice. Sometimes lots of practice.
For the RCA leads, I've heard there are crimp on RCA connectors. You might want to explore that avenue. Good luck with the "S" connectors...
The two most important things to remember when soldering are
1). The physical connection must be clean and solid before applying the solder. don't depend on the solder to hold the connection together. It only provides an oxygen free environment for the connection.
2) Don't just heat the solder and let it drop on tthe connection. You heat the connection, not the solder. The (cold) solder should melt on the connection (not the iron!) and smoothly flow over the connection.
Oh, one more thing. You don't need a heckuva lot of solder and don't move the connection until the solder hardens. A good solder joint will barely cover the connection and be shiny.