I just had to replace mine today after my fan crapped out 2 weeks ago (also only had super high speed only). Around these parts that resistor was b/o but I got mine in couple days ago so today after...
Full instructions on how to replace resistor are available at: http://karjama.com/brad/automotive/nissan-versa-maintenance-and-repairs/how-to-fix-fan-that-will-only-work-on-highest-setting-4/
It is located underneath your glove box. you can see 4 wires going and connecting to the resistor.It is connected by 2 screws. Its real easy to change it. Do not need to remove the glove box or...