What should I tell the 'rents? Or at least, how should I go about it?

It's hard to say because I don't know exactly what your relationship is with your family. It sounds like they're the type who don't want to address things that they don't understand or would feel uncomfortable with. I'm sure it's hard for you to talk to them about it too. I would say firstly, if you're not already seek counseling. Being trans gendered would be hard to go through without someone to talk to. Secondly I would say talk to them about it. Even if you don't get a reaction or resolve things initially it will come in the future after things will sink in. It must be very hard for but hang in there. You might want to consider finding a way to save money for the operation in the future. IF you want to talk further and delve more into detail please email me. Just know that there are people out there who understand and care about, such as me. Good luck sweetie.