If one of the objects you have offered up for auction is no longer available, you can withdraw it from the auction during the review days prior to the auction starting.
This is the period in which sellers can provide feedback on their objects before the auction is open for bidding.
To edit your object or contact the expert, go to > My offered lots (from the drop-down list at the right top hand corner of the website) and click on the object you'd like to edit.
From there you can follow the steps to edit and in the 4th step, you can contact the expert if you wish.
Please note that after the object is planned or in auction, you can no longer make any changes.