I’m a bit rusty with United award ticket fundamentals but I figured better to ask here first than spend a ton of time with an offshore phone rep. Back when I used to book United award tickets more frequently (pre-covid) I recall that United would barely ever make a ticket “change” instead resorting to cancelling and rebooking (with excuses like married segments, point to point, etc. etc.)

So here’s my current situation: I booked a United award for 2 PAX and a lap infant on LH in J routing ARN-MUC-LAX. Can I change my origin to something like Zurich or Dublin (given that the award space exists) without having to throw my MUC-LAX back into inventory and hope that it shows up again?

Also note that with a lap infant, I cannot make any ticket changes online. Website says that I must call.