Just looked at UPS tracking info Change Address button and says the following
Track with your UPS InfoNotice® Number (found above the barcode) and choose from up to four delivery change options:
Return to Sender
Deliver to a New Address
Reschedule Delivery -
Hold for Customer Collection
Note: Prior to the first delivery attempt, contact the sender to request a change in delivery instructions or to correct your delivery address.
Looks like you can only change it through Farnell if they would even do it but I doubt it prior to the first delivery attempt, makes sense incase someone got your Tracking No.
Got the same problem here, mine is coming Monday so have got to ring my boss Monday morning and beg for a day off as you should book holidays a couple of days in advance.
Can't complain though, I am sure it is a problem many would love to have