Mechanic Q: changing idler arm?

how do i chang it out

Mechanic Q: changing idler arm /pitmin arm?

how do i do it step by step

Mechanic Q: need to change idler arm /pitman arm?

need to know what to take off

Mechanic Q: oxygen sensor?

took truck to advance auto they put it on canner andtold me that it was 02 sensor right bank no1 under the driver side bought new one replaced it it was the wrong one need to know how the numbers go