Please see this post for a complete "How too" for the steps needed:
If you have a 95/97 D90 you dont need the crimp tool as the LED lights come already built, but this is not your case..but you really can get by without the tool with a set of wire cutters and a small electrical plier...
The LED lights have the same pattern as the NAS lights as close as you can get, much improved brightness is one of the reasons for these lights and completly sealed is another...I have had many customers buy brake lights first and then add turn signal afterwards as funds are available and vice versa...
I have been out traveling a lot lately and giving out my personal cell phone is not an option, but email is always answered.
It's really not that difficult a job and the LED lights fit nicely inside the mounting plinth and dont stick out at all.