CHECKOUT - How do you adjust order of elements

Hi I can see lots of discussion on the board about adjusting the order / elements in checkout but cannot see discussion on adjusting the order these elements appear on the screen.

For instance Id like to change where the "register / quick register" field group (highlighted red)appears. Where would I look to in this instance move that field group to the bottom of the checkout screen. Im pretty certain this question hasnt been posed on the forum so hope the answer might prove of use to other members of the board.

I appreciate your assistance with this question

Kate