Hi, I have a 2000 323i and my window stopped going up and it made a loud pop noise. First it would stop halfway, then I had a friend pulling it up by hand as I used the button. It would fall back down about halfway, then we pushed down and pulled up, then it just stayed all the way down and won't go up at all anymore. I can hear a grinding or clicking when I press the button. Any advice would be greatly appreciated. Also can I fix it myself?