One of the great benefits of the old-fashioned tubular handlebar is that you can, usually, replace the stock item with something that fits you better. As you know, when manufacturers design a bike they take into account a range of body sizes and shapes, so the final ergonomics might be pleasurable to no one and inoffensive to all. Changing to a different handlebar is pretty straightforward.
First, take some measurements to see what kind of bar will actually fit on your bike. The normal measurements are width, height, pullback and droop. Width and height are obvious, though some bar makers measure height from centerline to centerline, while others depict the total height from the bottom of the center section to the top of the outer section.
A straightedge laid across the bar will help you measure height (1); figure the center/center height as this measurement minus the one-bar diameter (7/8 inch for conventional bars, 1.0 inch for most cruiser handlebars). The pullback is simply how far back the bar ends are relative to the center section. Normally, when modders get in trouble it's usually because they've chosen a bar that's too flat or has too much pullback, so that the grips or switch pods smack the tank at full lock.
Also, measure the distance from the end of the grip to the inside edge of the last control perch (2) so you'll be able to determine later how much you can trim the new bar.
Start the actual swap by removing the old handlebar. Remove the bar ends and mirrors completely -- remember that mirrors can be amazingly unwieldy when the levers are off the bar. Remove the levers and hand controls one at a time and place them atop shop towels on the instrument cluster (3).
Remove the left-side switch cluster (4) after locating the small screws; beware, they may be two different lengths and need to go back from whence they came.
Dismantle the throttle-side cluster (5) and slide the throttle tube off the bar. You may have to remove one throttle cable to allow the barrel to slide off the end, but if you can leave it assembled, do so.
Loosen the bar mounts and take note of their orientation. Most Japanese bikes have staggered mounts (6); by design, one leg of the upper clamp fits flush to its corresponding leg on the triple clamp, while the remaining one has a gap.
Fit the new bar and hand-tighten the clamp. Sit on the bike and get a feel for the angle, width and pullback. Satisfied? Loosely install the switch clusters at the correct distance from the ends to accommodate the grips, and check for tank clearance at full lock (7).
If there's room and you like the overall width of the bar, the next step is to drill holes for the locating pins on the switch clusters. You can simply file the pins off, but you run the risk of the clusters rotating around the bar.
Mark the location and drill a 5mm hole (7/32 inch) along the centerline (8).
Mount the clutch and brake perches, switch clusters and grips (to make the slide on easier use compressed air with closed-end grips or give the insides a modest squirt of contact cleaner) and see if you still like the position. If you're happy, torque the main clamp, fit the bar ends and have a nice ride.