Okay so I tried the last option for the past few days and it seems Tiger is 'getting it'. I have the long leash on his harness and small leash on his collar. First time I give him the command calmly, 'Up', then second time I am more firm in my voice (but not mean), and after that I do pull the small leash on his collar. Today while coming back from the park, I simply opened the door and he just went on his own! Hooray for our regular routine again!! He loves going out, he always has!