This looks pretty identical to our one that i removed just before Christmas.
The handrail was made up of two parts, the curvy rail part i think was nailed into a backing/support bit of wood, which was then screwed into the walls.
I wouldn't just crowbar it off, because if it has been screwed into the walls then it'll leave a huge mess to repair.
Have a good look at the handrail, and you should be able to see imperfections, scrape away and you'll hopefully see a screw/nail that you can remove. Once you've removed them all, i got a chisel to tap between the backing board and the handrail - years of being painted means it's stuck to the backing board like glue. Once you've made a bit of a gap though, it's quite easy to prise it apart.
Once the handrail is off, you should be able to see the backing board much easier, and the screws that went into the wall were completely visible - they were hidden behind the handrail.
I managed to get ours off with absolute minimal damage and i've filled and sanded down level. At a glance you wouldn't see any imperfections, but closer look and you can obviously see where the layers of paint are higher on the visible part of the wall. It'll do us fine until we install a nicer looking handrail at some point in the future.