a<Enter><Space><Space><Escape>                  /* line break after {, indent following line with 2 spaces */
qq                                              /* start macro recording */
f{a<Enter><Space><Space><Space><Space><Escape>  /* line break after {, indent following line with 4 spaces */
2f,l.
2;l.
t}a<Enter><Space><Space><Escape>
e.x
q
@q
4@@
gg /* go to very first { of file */
%  /* go to matching bracket at end of file */
i<Enter><Escape> /* move it to a new line */
jdd /* delete last line of file */