Unfortunately I don't know anyone in your area, can't help there.
Removing the applied coating could be a lot of work. The safest way is to physically scrape it off. It's possible some of the coating could be removed with a pressure washer. Both of these removal methods could cause serous damage to the existing substrate if done improperly.
They can be combined. First washing then scraping. If it comes off easily now, as you indicated, then using the pressure washer should remove a bunch. Scraping can be used for areas that are well stuck to help smooth them, remove the rough pebble like texture.
There isn't a clear cut answer. It depends on the coating. The more it's stuck to the surface the less likely it will come off.