how do you delete the objects in create mission mode in infamous 2

Sucker Punch, creator of inFAMOUS, today announced a Mission Creator mode for Infamous 2. This means that we will now have the ability to create our own mission levels and share them with the community. There will be a public beta in early April, while Sign up information will be given out on the 14th of March. Details regarding the Mission Creator can be found below.