biblatex does not work with
.bst files the same way classical BibTeX does. In fact if you use the default Biber backend, no
.bst file is involved at all. (If you use BibTeX as
biblatex uses its
biblatex.bst but that does not control any formatting in the output and should not be modified.)
biblatex styles are defined with
.cbx and optionally
.lbx files. The idea is that
.bbx files contain the definitions for the bibliography style,
.cbx files contain the definitions of the citation style,
.dbx files contain additions to the data model (such a file is only required if a style wants to define new fields or entry types that are not present in the standard data model documented in the
.lbx files contain localisation/language definitions (
.lbx files are only needed if the style needs to change language-dependent stuff).
The first three files (if present) are usually called
<stylename>.dbx, while the
.lbx files are usually called
<language>-<style suffix>.lbx (though the naming scheme for
.lbx files is rather recent, older styles may use other conventions, but it is usually possible to tell the language and the style from the file name).
The Nature style of
biblatex-nature consists only of the two main files
If you find a file
nature.bst that has nothing to do with the output you get from
You can copy the
nature.cbx two files and rename them to
mynaturestyle.cbx, respectively. Then you can go about modifying the files as you wish.
.cbx files just contain normal LaTeX code, it is common not to copy the files at all, but to just apply the required redefinition in the preamble of your document (see for example create a hyperlink by using the url stored in the bibliography reference?).
You can find a bit more about where to put
biblatex modifications in Biblatex.cfg vs .cls vs .sty.
There is a nice introduction to simple
biblatex customisations at Guidelines for customizing biblatex styles.
Finally, it should be noted that
biblatex requires a different workflow from publishers than classical BibTeX or
thebibliography, so I would only use
biblatex in a journal submission if the publishers explicitly mentions that
biblatex should be used. Often publishers provide some guidance for LaTeX users (when they accept LaTeX submissions at all) and quite often they include hints about the bibliography as well.