Pry up the pebbles at the opening near the tree using a bottle opener (works for me) and once you get it started, you can just peel off the rest in chunks. Fill in the blanks where a lot of soil comes with the pebbles and do use warm water trickled around the edges to soften the glue, then scrape off with a butter knife. I also suggest repotting into a fast draining grit vs the (probable) peaty potting soil it's in (most 'potting' soil is mostly peat). Then you can water without being afraid of drowning it. Make sure you don't leave the pot in drain water, but put it up on large pebbles in a wide tray of water to humidity the foliage, and keep it in full sun throughout the day.

You can train it to be a bonsai tree. Those aerial roots will eventually become a trunk like structure when they reach the ground and get more nutrients and will be unrecognizable from the main trunk. Or just remove them if that's not what you're after.

I too would like to know the answer to this question. If you have ever seen a specimen grade tree of this variety you know what I mean. the "tubers" or above ground root structures are so intricate & magnificent. How do they do that? I have seen pics where it appears the tree's are bound w/ some sort of red strap like material to manipulate them. maybe it's a trade secret... or just time. H.

Too cold, likely sodden and no real sun = likely death for a ficus. But I suppose you could try an antifungal of some kind, and 15 hrs of bright light a day. Or read up on taking care of Ficus and then buy a new one.