Lots of good advice above; condensing what others have posted, this is how this LA resident would drive it:

Plan A. 405 South to 22 East. There is a carpool lane on the 405, none on the 22. Expect moderate to heavy traffic all the way down the 405. On the 22, the moment I saw traffic backed up, I would exit the 22, head north about a mile and then turn right on Katella Blvd and take it all the way into the stadium

Plan B. 105 East to 605 South. There is a carpool lane on the 105 and 605, but no carpool transition to the 605 from the 105. Expect moderate to heavy traffic on the 105 - the 105/605 merge is metered and gets quite heavy. Take 605 South to Cerritos Ave East and, at your leisure, make a right at some point to meet Kattella Blvd. which is the major street south of Cerritos Ave. (there is no Kattella Blvd. off-ramp from the 605 South).

Avoid the 91, 57 and the 5 at all costs.

KNX1070 AM Traffic every six min
KFWB AM Traffic "on the ones" :01, :11, :21, etc. unless there is a Dodger game.