Help on cleaning propane wall unit ignitor? the unit would run and quit, guess o2 sensor be cutting out....

the unit would run and quit, guess o2 sensor be cutting out. not be cleaned. how much trouble to take out ignitor and verbs the unit? i am assuming explicitly the culprit
Answers:    If it is the pilot is dirty and this is a unvented heater (they are the just ones with o2 sensors) only shut off kiln make sure flame is out and dust pilot near same canned nouns you would use to dust computer keyboard. Let stand a few minutes and relite pilot. Pilot should be blue and steam up end of assembly red hot.
There's simply one sensor on it. You will find it usually opposite the nouns where the ignitor is, it's a metal looking rod that sticks out into the flame nouns with with the sole purpose one wire connected to it. Just verbs the rod with a small cable brush or sandpaper.