No, you don't have to do that. You can start immediately without disconnecting. I have the same situation now but with a little more voltage
However, of course, before doing this, wear rubber gloves, if you do not want to have a chance to cheer up very well xD
I had the same situation, and I got a burn on my hand, and I also got a good shake. After that, my wiring in the house broke down, and I had to contact the service bates-electric.com
and the benefit they repaired quickly.
So be careful, and even better, just contact a person who knows it well, or contact some service. It is better to pay money for this than to lose an arm or fingers