Learning Songs Advice

I play in a good band with 3 guitar players.
Lately, we have been learning some more complex material and I thought I should post.
The other lead player seems to get confused on what he is hearing concerning harmony notes.
He seems to get overly complicated and frustrated.

I have 30 years experience and while I am not an expert, I am pretty good at nailing the notes and tone. I was wondering what techniques you players use?

PS I recently purchased a guitar trainer box that should help and my home stereo is killer, true studio monitor set up.

A few tips I have used are:

Listen to the song one side of the stereo field at a time.

If you have the ability, flip the phase on one side of the stereo field and listen.

Use an application such as Winamp and the Pacemaker plugin to "remove vocals". This technique is similar, but not the same as switching the phase of one side.

Use an application such as "Transcribe!" by Seventhstring Software to work out all kinds of options, including having the software tell you the note(s) being played at any specific point in a song.

Most of these solutions are free, or near free, and some require actually purchasing software.

I have no idea how to convince the other players which notes are the right ones, other than record what you've played as you hear it, then listen to the result compared to the original. Often times, it's just a tightrope not worthy of stepping on. If the guy refuses to play something the correct way (either because he can't technically accomplish it or he just doesn't care), then you have to decide whether to replace him or live with it.

When I get stuck I either find a good transcription, or do my best to transcribe the song my self using some thing like this. Then I start learning the song begining from the last measure. That way as I start playing through the song (as oppose to memorizing it) I am moving in to more familiar territory as I go.

Thanks a bunch!
All good ideas