For myself, I had Randy Hawkins chop my tail for me. I didn't have the courage to do it myself.
For the plate, I just used the two T27 screws that held the tail on to hold my plate. I think I had to drill new holes in my plate for it to line up. Never had an issue with the police. The plate sits flush, and if I ever got pulled over for it, I'd just have to grab the bottom and bend it out to make it more visible. But from standing behind the bike, you can see it pretty well.
As for turn signals, with the tail chop it got rid of the stock mounting holes. I rolled for two years without rear signals, as it is legal here to do so (as long as you use proper hand signals.) I finally ended up buying some short LED strips and ran them down the sub frame. The wires fit perfectly through small gaps where the tail mounted.
The only issue I have with my set up is I do not have a plate light. Yes, it's law here... I was thinking of getting some of the LED bolts to replace the T27 screws with that hold the plate on. But due to the wild life here, ie bears, moose, deer, I don't do a lot of night riding. But again, never had any grief over not having the light.
Sorry the pics are kind of shitty. I took them for a different thread. But I hope it gives you an idea.
This pic you can see how I connected the LED strips, and ran the wires through the gap...
This pic again you can see that, and see how I used the stock torx screws to mount the plate. I had to bend it a bit, but again I've had zero issues in the 2 or 3 years Ive been running it. Your laws may vary.
As for integrated lights, check out XB Lights.com their banner is on the right ------------->