I don't know if I've mentioned this before, but there's a pretty easy way to get rid of that one Ewok's speeder bike adventure.

Just make it so there's only ONE guard at the secret entrance, simply paint the other guards out. Han then comments "Not bad for a little furball, there's only one of 'em". Leia, "It only takes one to sound the alarm", "Then we'll do it real quiet like".

Then, cut straight to Han attracting the single guard to the mini ambush. It also ties in better with the idea that the Emperor was baiting them all along seeing as it was just too easy.