Did mine on my 80 Special last year. It was pretty easy.
How I did it;
Removed the gas tank and headlight. Unplugged everything inside the headlight bucket and pulled the old wire harness out of the headlight bucket. Then fed the new harness in the headlight bucket like the old one was, plugged stuff in. Then I just followed the two harnesses back through the bike, unplugging the old and plugging in the new. Did it this way so that all the wires went in their stock locations. Then add zip ties every so often, put the headlight and tank back on and I was done.
It was real simple and took me probably less 20 minutes. No more electrical issues!
Only if I could find a new wire harness for my GF's CB650, that bike has been an electrical nightmare.