full-blown hotline miami save editor, that supports new (updated) version of the game
to use the thing download the latest release and run it.
it should find a savefile and load it automagically, but, in case something goes wrong, you can load it yourself, using load savefile button on top. select a savedata.sav file in %USERPROFILE%\My Games\HotlineMiami\ and select it.
after changes, hit save savefile button, and you are good to go.
msys2: $ make windows