Can't check steering fluid

I just got my 2003 a4 a month ago and I've started hearing noises when turning at low speeds.  I tried to check the steering fluid but I can't pop the lid - is this normal?  Me and a few friends have tried with no luck. 

Since the manual is very vague about the steering fluid, other than requiring special hydraulic fluid, I'm wondering if I'm not supposed to take off that lid and if I'm going to have to bring it in to the shop.

Umm....you should be able to take off the green cap for the power-steering...it just unscrews like any other cap. If its stuck you may have another problem.