for the front end, either push the forks through the triple tree or change the springs in the fork tubes... do a search...lots of info will come up. The rear end can be lowered by using short shocks or lowering blocks. If you have rear discs you might have problems with using lowering blocks, my shock was hitting the caliper when I installed the block. Shaving your seat will help also.
I have a 74, 75, 78 cb750...11" rear shocks, tubes pushed through the triple tree 2", and cafe racer seat. I'm 5'3" and I'm flat footing at stoplights.