Hello,
I think in this case you need a level converter between 5 and 3.3V. I have tried some thing like this to interface a sim card directly to the 5V microcontroller, at that time i used a simple level converter using a not gate 74HC04 and given 3.3V to this inverter IC, so 5V from the pic will be converted to 3.3V. You can also use a transistor drive circuit i have attached. I think it should work.
