I recorded a macro of my doing this and adapted it, missing out the
lines which were just the defaults and was left with:

Sub blah()
With ActiveSheet.PageSetup
.FitToPagesWide = 1
.FitToPagesTall = 1
End With
Selection.PrintOut
End Sub

which seems to work fine. Record your own macro if you want to alter
other aspects which I've omitted here.