We are actually starting to do this with Angel.
We initially put on the harness so she could get used to it. It took some time and she did the same as others where she would just plop right down then and there and not move and become sulky after we took it off.
After she got used to the harness phase we attached her to a leash and started walking her around inside the house. Yet again she would do the same thing but got a tad better.
Just this past Saturday we took her out for her first walk down a nearby street. I would say it was a block. She did stop a few times and just laid down. But with a slight pull/nudge on the leash she got right back up and started to walk.
By the end of the street she was trying to jump into DJ30's lap (she was kneeeling down). I think that was a sign she was "done". Plus it was very hot out that day and she was panting. So we scooped her up and carried her home.
All in all I think it was successful. You just have to take it in strides/phases. Good luck
