Deleting edges and face problem I simply want to delete those things that are selected, edges and face. I removed doubles, tried every option which offers when I press "x" but with some options nothing happens, and with some all mesh above this gets messed up.
hit the 1 key to go to Vertex select mode. Deselect everything, tap B for Box select and drag box around bottom vertices to select those. 


Then hit X and select vertices to delete.