I know this cliche gets old, but if you are unsure of this procedure maybe you should get a professional to do it. This is certainly a commercial application and it may not be legal or code for you to be working in the panel.
A bolt-on breaker panel is no place for the inexperienced to be working.
I use an insulated screwdriver since commercially/industrially most times it is not feasible to shut down the whole panel to replace a breaker, unless you do it at an off time so no one is interrupted.
Please consider the consequences of a slight mistake.
Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.