Try to sing the notes of the the pitches you hear. not with just these 3 songs but with the bass part in EVERY song you listen to. get those songs you need to have down in a week or w/e and listen to them in the morning, after noon, evening, before bed, in the car and sing those bass parts hear it in your head and and then pick up a bass and keep the melody singing in your mind/hum it and start to find the notes.
if you can't find all the notes, but some, write it down. wether you can write bass clef, tab, or w/e Find a way to notate it down, best scenario would to break it up into 4/4 bars, and write where each note lands on the beat or off beat and go back to the parts you don't know.
I've been struggling with this as well.
my buddy is so good its like he doesn't know what it is like to not know what to play, and he doesn't communicate well, often times i get " I'm not a music teacher learn it your self" and he gives me an attitude. really aggrevating. I mean he has the knowledge and talent, if he could take a more constructive approach and be like "hey man, maybe try moving up a half step" or "hey man you're playing the note in this certain part wrong, play a C instead of that B!" and not "dude stop playing the same fuking wrong stuff" my "band" would get somewhere.
I myself, play bass but i also dabble a bit on guitar and recently keys, so when i'm jamming with other people who aren't nearly as talented, and say they don't know the chords to a bassline but i do I let them know and then we have a good time jamming and we sound good.
it really goes to show that doesn't matter how talented a guitarist is he will make the band function like crap if he has a big ego and can't communicate(i guess anyone in a band can do that but its always the damn expert guitard in my experience),