Sun Effect

I want to put a Sun onto an existing photo that looks very similar to this
with all of the beams coming out, to make it look very realistic. Has anyone got any tips on how to create this or a good tutorial i could look at?
Thanks,
Joel

Use brushes, smudge tool, layer modes etc. It's not like, do it like this or that I'm afraid.

Or just get yourself a masive lens flare of course, but I'm sure you've tried that already...

you can use effect lenfare or lightning and change the color of the sun...very simple