Hmm. I think I would probably carefully trim the excess, then buff with leather conditioner and/or neutral shoe polish all over the piece. Trying to glue it will probably look worse.
Iamtootallforthis is right, I don't think I would recommend trying to match the colour and finish, probably best to just renew the whole thing and make it blend in as much as possible.
However--if you go into a shoe repair shop and you can get a polish that matches the colour very well, that might be your best bet if you are really wanting to hide it. (Dye won't work, will be too dark)
Hope this helps