Thermostat Help/Diag Needed!

I have a 96 3.8L firebird and the problem I have is when I'm driving I get a strong smell of antfreeze and it is also present when i exit the vehicle. And just yesterday my car would be running at abnormally high temps then spike up to the red (260+) then come back down. It continued to do this for the whole drive. Is this a thermostat and low coolant issue? How do I go about changing out the thermostat? Can someone please help me?
Thanks in advance I really appreciate all you guys and your wealth of knowledge!

With the coolant smell and spiking temps I'd check the water pump for signs of leakage. The temp spikes could be a thermostat but the coolant smell is either a leak (possibly boiling over and out the overflow) or even worse...blown head gasket.

also, since you smell it while driving, check underneath the passenger side floormat and see if it's wet with antifreeze. if so, your heater core is leaking.

The spiking and dropping temps are many times signs of air in the system.