How to open hood of a 2003 bmw 530i
http://5series.net/info/2004_5_Series_Manual_US.pdf -- this manual might help you
Page 10 of manual. Item marked 13
http://www.bmwtips.com/OwnersManuals/2002-5ser.pdf -- here's one for a 2002.
Page 137 in 2002 manual it appears to be the same as the 2004
You could also go to a BMW dealer and ask them. Just a thought. Shouldn't cost you more than $75.00 for the consult. Just kidding.