that's actually Eddie Van halen doing the solo and Steve Lukather playing rythm guitar.
some cool solo's worth checking out if you get a chance:
I never knew that, till I either read it here, or another friend of mine mentioned it.
The other day I'm working out and the song comes on, and I listened a bit closer when the solo came on. You can totally tell, once your attuned to it, that it's Eddie. One of those "he plays one lick/note and you can tell it's < insert name >" kind of things.
I wasn't sure if he played the rhythm part or not, but thanks for clarification on that.
And as far as "winging" a solo, it's not that hard to do. Lots of guys like to plan solos out and whatnot, but to someone like Ed or another "best guitar player," it's really just like brushing his or her teeth...