>To get an Exp.Share, go to the Radio Tower in Goldenrod City every day and check their lottery drawings. It checks your Trainer ID number and those of the Original Trainers of all your Pokemon. If the last three digits match, you win the Exp. Share.
>And, of course, trade the Red Scale to Mr. Pokemon.
The simplest way is to give the Red Scale to Mr. Pokemon.
Hope this helps!