How hard is it to replace throttle body on a 2002 Mercedes benz ml320

What is your question?

My car sometimes wont go when I give it gas, used autozones diagnostic to see what check engine light was on,it said throttle pedal sensor, I don't have a lot of money, friend is going to do it, I just want to know how difficult it is.I already bought the throttle body part.

What makes this problem better or worse?

Nothing, it just sometimes wont go when I give it gas

How long has your 2002 Mercedes-Benz ML320 had this problem?

Few weeks