<SPAN class=cs_misspelled>==</SPAN> <SPAN class=cs_misspelled>==</SPAN> Use a good quality <SPAN class=cs_misspelled>pentrating</SPAN> lubricant and be patient. You may to spray some on and let it set it and then spray some more on. Use a flare nut wrench to avoid rounding off all of the corners of the nut. If that does not work, you can resort to the <SPAN class=cs_misspelled>vise-grips.</SPAN>
It has been my <SPAN style="POSITION: static" textContent="null">experience</SPAN> that if you start with <SPAN style="POSITION: static" textContent="null">vise-grips</SPAN> and apply enough pressure on each flat to dislodge the threads from wheel <SPAN style="POSITION: static" class=cs_misspelled>cylinder (do</SPAN> not attempt to turn fitting at this point) then when you clamp on the last flat and turn the <SPAN style="POSITION: static" textContent="null">fitting</SPAN> it will come out very <SPAN style="POSITION: static" textContent="null">easily.</SPAN>
Could be from several sources such as master cylinder, wheel cylinders, calipers, brake hoses and rusted brake lines. All of which can be rebuilt or replaced. Have it looked at as soon as possible!
Hit it with a hammer
Hacksaw
You can try soaking it in Vinegar.
Put in Hot water
A cutting torch is one answer.
Most rust can be removed by a steel brush if its not to rusted
a large hammer
A magnet
Lug nuts are still on, wheel is rusted to the hub.
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.
Your going to need to get a special puller if its rusted on, usually if its new or not rusty you can just remove the bolt and hit it with a hammer a few times and it will come right off but if it is rusted then you should get a crankshaft dampner puller