for the second step it is recommended to use the commands (!set type insl vine and !set type plnt vine), in the third you need to replace GOL so the commands will not work. just draw on BRAN some other element resistant to heat (here: aray) and apply the command !set type life 0, then in the freed space draw VINE and use commands (here: !set type aray 0). in the fourth just repeat what you did in the second step, then click on PC again and select flood there.
there seems to be no replace mod on the mobile version, it is better to use command/outline methods
click on the red sign in the save, do what it says (the console power button is the second one from the top), click on the LUA icon that appears on the right, look for and install the "PC controls for android" mod. After that, you will see the PC icon, click on it and enable undo/redo, you will see a UI with the "1-Frame" button, this button skips one frame.
how to press f and enter the replace mode
my method involves add tool