Not terribly hard as reflows go I expect but a little more complex than simple mcpcbs.
There are 8 emitters and 3 wires so more things to go wrong. Removing the mcpcb will be faiy easy: dissemble the light (one big screw at the top), desolder 3 wires (remembering which goes where) and remove 2 screws.
Being a large mcpcb it will need a fair amount of heat to melt the solder, a skillet or direct flame will help.
You may also notice the tint goes rosy when ramping between those tints