CPU Heatsink Help

I've been a console gamer for most of my life but recently switch to PC, and i'm loving it so far. I built a pretty decent PC but i am still new to this and i'm not completely comfortable with upgrading and switching parts yet so i'm asking for help. My CPU fan came with the CPU and it is really really loud. I want a quiet and good fan but i don't know what to look for. any suggestions?? And how do i switch it out? without ruining anything haha

Thanks 

what motherboard do you have and case?  Switching the cpu heatsink is easy if your case has a cpu cut out.

my case is awful...its a coolermaster 430 black elite (http://tinyurl.com/393pqgy) and my motherboard is a Gigabyte 990FXA-UD3 (http://tinyurl.com/44cnykp)

i was on a budget at the time. my cpu is FX 8350