Often the hose which is under the Pentosin reservoir. That is not a high pressure hose. I cut about 1 cm off and attached it again and used a new hose clamp and it does not leak anymore.
All high pressure hoses start to leak when they get old. I replaced them all.
Old ones
http://www.bimmerboard.com/members/shogun/CIMG4994.jpg
This is possible
http://www.bimmerboard.com/forums/posts/269769/
But not the most elegant way. I went to a hydraulic shop, they cut of the crimped part, used new hoses and crimped the sleeves on the BMW pipes.
http://www.bimmerboard.com/forums/posts/270221
Or buy new ones from autohausaz.com, they have good prices