Spray them liberally with penetrating oil (I'm partial to PB Blaster, personally). If that doesn't do it, cut them off... you can use a torch if it is safe to do so, or a grinder.
Put in Hot water
Most rust can be removed by a steel brush if its not to rusted
Rusted iron is not pure iron; it is an iron oxide.
DO NOT CLEN WITH LIQUID!!!! I recommend you take a tissue place it over a coin and very carefully and slowly scrape the rusted areas.{Be careful not to scrape the surface of the coin or you will diminish its value}
yes
Hit it with a hammer
Hacksaw
A cutting torch is one answer.
Put in Hot water
raise the trunk. pull back the carpeting. remove the 5 plastic wingnuts holding the light assembly in. separate the light assembly from the car. twist and remove the bulb. installation is reverse.
Pop the trunk, pull back the trunk liner, remove the 5 plastic screws/wingnuts, and separate light assembly from the car, remove the bulbs and replace.
A magnet
a large hammer
In the third-gen Camaros and Firebirds, you must first remove the inside-rear of the trunk. That will give you access to several large plastic 'wingnuts' (usually black). Remove the wingnuts on the side that has the blown bulb. This will leave a stud that sticks in to the trunk where each of the wingnuts were. Push gently out on the studs, the tail light lens will loosen and can be pulled off the car. You can change the bulb by pushing in and turning. I always buy the higher cost, long life bulbs. This is too much of a pain to do over and over. It's also a good chance to clean the tail light lens and the area around it.
open the rear hatch. pull back the carpet/felt. remove the 5 plastic screws/wingnuts. and separate the light housing from the vehicle. twist the bulbs to remove. install is reverse.
Rusting bolts normally indicates that the bolts are brittle. Taking a pair of water pump pliers and squeezing really hard will most of the time break the rusted bolt so you can remove the toilet seat. Otherwise depending on the type of toilet seat installed, you can drill a hole right through exactly where the rusted bolts slot in, so helping you remove the toilet seat.
Lug nuts are still on, wheel is rusted to the hub.