Anything dried up and dead should be trimmed off. Assuming the plant is still alive, which it likely is, it will regrow soon. The plant should regrow regardless of whether you trim off the dead leaves, so this is just for aesthetics. If you aren't sure what's dead and what's alive, and you don't mind the appearance, wait for new growth before trimming. That way, you can be sure you're only trimming dead material, and not live parts.