With care it's not too tricky.
Good lighting helps too.
Get the throttle cables up and clear, out of the way of the pulley and cable bracket.
Flexible inlet rubbers (or new ones if possible) will help too, with the clips loosened off.
Also loosen the large clip between the manifold on the oval connector, then use a bungy to hold the manifold against the frame which gives a few mm extra clearance to ease the carb bank into position.
Angle the back of the carbs down as they are moved into position from the RHS, then insert them into the 4 insulator rubbers (again, clips loosened). Quite a tight fit so a tiny amount of WD applied by finger to each carb spigot helps.
The rubber connectors can then be adjusted/rotated correctly. I put a smidge of WD on the inside of each one to help them onto the carb inlets.
Then have some more fun routing the four drain tubes and two vent tubes between the engine and swing arm !