Yea, the thermostat is pretty straightforward. A bit more challenging if you have an auto, only cause you have to use a 32mm wrench to get the fan off first. Otherwise pretty simple.
Check for oil, should be pretty easy. If you are smelling something, it may be oil dripping onto the exhaust manifold. When facing the car from the front bumper, look to the left side of the engine (passenger side) and look on the metal heat shield. If there is oil all over it, that may be your culprit.
P46 Projectors + FX-R Retrofit + 6k D2S / 60 LED AE's / Smoked LED Tails / Smoked Turn and Side Markers / BSW 10" Sub /ZHP Knob / Matte Black Grills / DICE / Parrot + Connects2 / OEM Alternative Alarm Mod / Clutch Switch Delay Mod / M3 Rep Front Bumper / 3M Black CF Di-Noc Wrap / K&N Intake / 35% Tint All Around / Black Short Eurotray / 545i Shifter