Finally, I did it! I bought a ball joint puller and pushed the control arm out easily. The rest of work is pretty streight foward, just put the new control arm on and replace the two nets and tighten the nets. All done. It took 2 hours to do it including test driving. Perfect!

__________________
--2004 E53 X5 4.8is - ECE version; right hand drive; Located in Hong Kong; ext. black sapphire metallic; int. leather black; adaptive dynamic bi-xenon headlights; 16:9 onboard monitor w/o navigation; 20" genuine BMW Y-spoke 214 wheels with Bridgestone Dueler H/P Sport tires; Int. rear view mirror w/ compass.