there is nothing overly special. You will know how to do it, hell, everything that is on the original handlebar has to move to the new one, piece by piece. Anyhow, secure bike first, and then:
a. Put a thick piece of cloth on the front of the gas tank
b. loosen everything on the old bar a bit, eases removal later. Once you do that, you will understand how everything moves and where goes what.
c. take riser caps off,
d. pick up and slide old bar with everything on it on the gas tank, secure it there somehow (tape, bungee??)
e. center new bar on risers, return and tighten riser caps. Measure and double check if all is OK and tight.
f. Start moving switches, levers, gas, brake, everything piece by piece.
g. Do not overtighten anything yet, you will play with angles of levers and switches after you sit on the bike and straighten it. Tighten all controls in place when you are happy with how it sits.

One consideration is length of the new bar. If your drag is absurdly long, cables may turn up too short. No luck tonight then. Second is Philips head screws on switches, tap them lightly before loosening, so you don't strip them. If you do - no biggy, replace with chromed allen heads