Putting all my videos on to one YouTube channel

I seem to have two YouTube channels. I need to have someone close one of these down and move all my posted videos to just one YouTube channel. I know the names use on both YouTube channels and the password for the one I wnat to close down. But I haven't a clue how to get into the one where I want to put all my videos and which I want to come up each time I log in to watch other people's videos on YouTube

I have a feeling this may be something we need to do on the phone as YouTube or gmail will probably send some kind of access codes to my phone and you'll need these to close down the Youtube account I don't want and to get me into the YouTube account I do want.

Please only reply if you are British, live in the UK and English is your first language as we may need to do this on the phone. And if you can help with this very small job, please do NOT use AI to write your proposal