Jesus was a glorious angelic being, but not Jehovah.
Establish that Jehovah does not share his glory (, 48:11). Then show that Jesus claims to have shared it before the world existed.
Simple logical fork using JW-accepted texts. Jehovah doesn't share glory; Jesus had it; therefore Jesus is Jehovah.
Jehovah gave Jesus reflected glory.
Jesus says 'the glory I had WITH you' — shared glory, not reflected. Isaiah says Jehovah will NOT give his glory to another. Period.
Glory is one thing — but only Jehovah has the unique attributes of God.
Then look at heart-searching — an attribute the Old Testament reserves for Jehovah alone. (NWT): "I, Jehovah, am searching the heart, examining the innermost thoughts, to give to each one according to his ways." That is exclusive — only Jehovah knows what is in a person's mind. Now turn to (NWT). Who is speaking? Verse 18 names him: "the Son of God." And what does the Son of God say in verse 23? "All the congregations will know that I am the one who searches the kidneys and hearts, and I will give to each one of you according to your deeds." That is identical Old Testament Jehovah language — "searches the heart, gives to each according to his deeds" — applied by Jesus to himself. The Son shares the very attribute the Watchtower says belongs only to Jehovah.
Keep it simple. The logical fork does the work.
Read and 48:11 until you can quote Jehovah's refusal to give his glory to another, then read the opening of Jesus' prayer in John 17 and learn what verse 5 says he had with the Father before the world existed. Check those verses in the NWT so the argument rests on their own Bible. Practise the logical fork aloud until it takes three sentences: Jehovah does not share his glory, Jesus had it, so who is Jesus? Expect 'Jehovah gave Jesus reflected glory'; rehearse the reply that Jesus speaks of glory he had with the Father, and have and (with verse 18, which names the speaker) ready if they turn to other divine attributes.