Living in SoCal you will want to paint the exposed trunk with Tree White to prevent sun scald.

As for the shape of your tree its really a preference thing as there is more than one shape that works. It will put out lots of new shoots that you can either train into branches or that you can cut off. It really all depends on how you want it to look. The bushy round shape does seam to be the preferred method at this time though.

paint the now exposed bark IMMEDIATELY with white paint to prevent sun burn. The sun this time of year will burn it really fast. This is REALLY important. You can use paper to wrap it instead but I don't think it works as well and it harbors bugs. Paint it the best way to go. a small can and a cheep throw away mini roller will get the job done quickly. Indoor latex, bright white (no oil base paint).
You may also want to get a little mulch down where the ground is no longer shaded. Do not let the mulch touch the trunk, just up close to it.
Watch for suckers from the root stock. You may get them now after that sort of pruning.

Is divorce and option?