Getting E+ at T-24 with check-in on AC first leg
 

Have an upcoming round trip from HNL to YYZ. Outbound is all on UA via ORD but return has the first leg on AC switching to UA at LAX. Already aware of the terminal change and needing to re-clear security. Have a long layover for this. Wondering though since I am silver how to go about getting E+ for the second leg on UA at T-24? Will I have to OCLI with AC first and then go to the UA site afterward to select seats, or will I need to wait longer until T-24 for the UA segment and then run a second OLCI for the E+ seat?

When you get to T-24 for united leg, call the elite line and have them switch you to an E+ seat. Better to wait to do OLCI until after you've done this if possible.