Here is what I do 2 days ago with my brake.
Buy front and rear brake pads from BMW + 2 new sensors = $200
Get my friend who is a expert mechanic to put them on = $100
No problems at all. The guy has everything he needs in his shop, and he has a lot of knowledge to get the job done right. He told me other brand name pads might make noise. so go OEM. and you gotta know what you are doing. otherwise, you just waste your time and efforts.

so do i need to change the brake sensors too? the lite is still on,,,??!!

the brake squeal is gone ,the rear was the problem,,i put some glue on the pads,thanks to everyone for help me with this issue!,thanks