Can anyone help me get rid of this giant mailbox?

I am having a similar issue with a guitar. My sim went to play his guitar, but for whatever reason, he chose to go across the street. Then when he was done, he put the guitar down. So now there is a guitar in the middle of the sidewalk and nothing I can do about it. He can still play it, but he can't put it in his inventory and I can't reset it or delete it. The limitations of those public spaces are awful!