I cant add loop cuts I have a model and want to shrink or press or bend on red axis show in the image to make the shape as shown in reference image. I cant add loop cut &amp; if i add sub division modifier i loose all the sharpness of the edges. U can try with my model i have attach the file.....

Added lattice and modified little bit to get the shape



confused problem 


with the reference video i have yet to error
press Shift+A and add a lattice

after that, select the object to be deformed and add a lattice modifier
 Under the modifier, make sure you select the lattice as the object  select your lattice, and go to edit mode, pressing TAB key; press Shift+leftclick to select the 4 vertices on the -Y direction of the lattice, press S to scale them. I've uploaded your blend file with the lattice: