Squeaky idler pulley
 

Had a very subtle squeak noise on cold starts that has become progressively worse over the past few days. I have very little experience with all of this, but haven't had any issues replacing engine components on my own so far. Do you think replacing the idler pulley is a job on par for a DIYer? Best friend works as a mechanic so I pay him for help occasionally, but $ is a little tight and I dislike asking for favors.

Also plan on replacing my lifters/rocker arm, so hopefully I don't find a way to brick my engine. I got $5 that says I do somehow.