I am a tenor 2. I am currently wanting to extend my vocal range without a vocal coach. I currently...?

I currently do not drive so I can not get a vocal coach at the moment. I want to somehow extend my "full voice" range to at the most, a alto 2. I am not looking to get my falsetto range to an alto 2 but I would like to work on my tone and vocal capabilities with raising the vocal range level.