It would not be super difficult to install the frets yourself, but it would cost you a bit of money for materials (fret wire). When I was into building guitars, I got a lot of supplies from Stewart MacDonald. Your can spend a small fortune getting the "proper" tools to do it (a press to install the wire, a fret-wire radiusing tool to match the wire to the neck's curve, the list goes on), but I think it could be done with some basic tools like a rubber mallet, side cutters and a flat bastard file.
It's hard to say if it's worth while, without actually seeing the condition of the neck. It could be warped or twisted, in which case replacing the frets would be pointless. You'd have to replace the entire fretboard to get the frets level. A properly adusted neck should have a very slight bow to it, to keep the strings from buzzing on the higher frets when you play a note.
You might want to replace the fretboard anyway - it appears that there was some tearout when the old frets were removed. Depends how picky you want to get.
Check out Stewart Macdonald for materials and see if you think it's worth it. There is a ton of how-to info there too. I'd look into it a bit more for you, but I'm at work at the moment.