Removing Polygons
 

I've used a cube polygon to create a body, and now I'm at the foot part of the model. Well...I'm not crazy where I put all my vertex points and edge loops, and would like to remove them and start over...can someone tell me how I'm supposed to do that without messing the rest of the model up? I tried just deleting the edges, faces, and vertices but I was eventually left with faces I with floating faces everywhere my foot used to be...messed it up and had to start over. So people, any suggestions would be appreciated! Thanks!