Your pictures seem to show the knuckle & sleeve surfaces are clean. But, I'd try a gentle metal polish that might remove oxide, but not remove healthy steel or aluminum. (Any opinions here as to the effects on the steel-aluminium interface?) In any case -- no sanding!
Grease may be a little too thick; I'd try some light weight oil (Mobil1 5w-30 for example).
Is it possible the sleeves got slightly distorted (ie, compressed & "fattened") when the ball studs were pressed out of the sleeves?
As I previously noted, mine went back in easily by finger pressure, to the point I was afraid it was too loose. But, after I inserted and torqued the nut everything was tight again. The ends were probably off on my '96 in 1999 when the EPS was replaced under warranty. They hadn't been touched since then until 2009.
Perhaps if you can get the sleeve started by hand, there may be enough length on the tied rod end stud to pull the sleeve through using the tie-rod end ball stud & nut? Just make sure you also install the steel cap on the top side first so the nut doesn't score the aluminum on the knuckle.
Good luck.