How do you replace neutral safety switch on 1995 Buick Park Avenue?

Hi under the hood follow your shift cable comeing out of the firewall to the transmission .where this connects to the transmission is where your nss is located it has a plug on it and is bolted with two bolts remove the plug remove the bolts unhook the cable. raise part up reinstall.

can it be bypassed by unplugging it?

well it is being bypassed by starting it in neutral if you unplug it then it will not start at all. you can bypass it but it will start then in any gear

How can you bypass it?

you can bypass it by useing a paper clip to jump two terminals together . you have to detirmine which two.check for power do not jump any power wires only non powered.