Justin put the broken piece in pot or just lay it on a bench, and give it plenty of air circulation, when you see roots replant it. The bigger the trunk the longer it may take, it needs to heal or put in the smallest pot it can fit into with dry mix, wait six week or more until it is rooted down then water. Don't water unless you know that roots have formed. Justin trim off some of the top growing tips of branches when you do this. Don't toss out the old trunk leave it alone it may come up with new growth as well unless it is rotted. Don't water it either. Norma

In general the cut should dry 1wk for every inch of diameter. So your looking at 12wks minimum, at this time of year longer. I did this with a 4in diameter Tylecodon and it took 8wks to completely callus and another 4 till I saw roots.

I'm a big fan of applying ground cinnamon to the open cut. It seems to help make it callus faster, and the anti-fungal properties of cinnamon may prevent some nasties from taking hold.

Just to repeat the excellent advice from above:
1) Let the cut dry completely before potting
2) Pot into dry, fast draining soil
3) Don't even think about watering until you are sure it has roots (lots of new leaves is a good indication)
4) Take some picture and share with us! ;-)

Hi,

I’ve just snapped mine 1 inch into ground level trying to move it around. It is still standing on the top of the broken trunk. should I just leave it? it is quite large.

It's probably too late to tell you no, don't leave it, it will rot