When I install update 58 do I need to do anything to the dalek mod files or will it do it’s self when I replace the java (update 57)

Nope, all you need to do is this:

Go to .minecraft and then the 'mods' folder

Get rid of update 57.1 (it might be worth keeping it somewhere, just not in the .minecraft folder)

Place update 58 in the mods folder

Run minecraft with forge (1.12.2)

These steps should work. Hope they help!

-DT10