Changing appendix headings from "A" to "Appendix A"

[Peter Bowyer]

Hi,

Apologies for what I imagine is a common question, yet I cannot find 
it in the wiki or mailing list archive.  I've written an article with 
an appendix in LyX 1.3.7 using the koma-script article layout.  I'd 
like to change the appendix headings from just
<letter>: My title
to
Appendix <letter>: My title
How is this best achieved?  I'm guessing there's a way using \renewcommand?

Thanks,
Peter