2 choices...going east
1. Shortest is the last exit before the I-10 tunnel, it goes thru downtown to the Bay Bridge exit which you use to get back to I-10.
2. Longer but easier is I-65 about 9 miles to I-165...then 2nd exit, the same Bay Bridge exit, jus from a different direction.
From the east going west just as your about to clear the I-10 bay bridge you'll see the sineage for US-90 bay bridge and then it's the reverse of the other choices.