I want to know if others here has done it.
haven't done it personally, but here are some user experiences pulled from reddit. it sounds like it takes some back and forth with coinbase support, but most people get it sorted out within a few days to a couple weeks:
https://www.reddit.com/r/CoinBase/comments/6n1car/got_a_new_phone_now_locked_out/dpegyhv/?context=8&depth=9
https://www.reddit.com/r/CoinBase/comments/81i2sc/lost_2fa/dv3av8s/
https://www.reddit.com/r/Bitcoin/comments/7cyd16/locked_out_of_coinbase_after_phone_change/drq5mtr/
https://www.reddit.com/r/CoinBase/comments/81i2sc/lost_2fa/dv40x6o/
https://www.reddit.com/r/CoinBase/comments/7orvx4/lost_google_2fa_authentication/dsbu9kw/
and this is what coinbase's support page says to do now:
Contact our support team and let us know that you've lost both your Authenticator app and phone number.
For the fastest resolution, please select "Login Issue" as the category and "2 Factor Authentication - Authenticator" as the sub-category.