Anyone have a link to detailed instructions on how to change the rear sight? Also----how to make sure its in properly? Or is it a guessing game at the range making adjustments...I just got my euro sight (the "u" shaped glock-like sight) in the mail today. FYI, paid $10 for it on ebay, its brand new. I can give the sellers information to anyone who wants it too, just to make sure you buy from them...they had more I think!