Take 880 south to 280 North , WAY faster (i do this 3 times a week!)
Take 19th Ave exit off 280 There is a right exit for brotherhood, It loops Right and goes back west under the road you were on
From there the mapquest looks good:
14: Turn LEFT onto LAKE MERCED BLVD. 0.50 miles

15: Turn SLIGHT RIGHT onto JOHN MUIR DR. 1.12 miles

16: Stay straight to go onto SKYLINE BLVD. 0.53 miles

17: Turn RIGHT onto HARDING RD. 0.04 miles

Brotherhood basically dead ends into lake merced. You are then tryng to go around the lake to the other side and left right right is the shortest way to go