remove glasses glare

[jaha]

Hi guys, I'm new and this is my first post. I would like to remove the glasses glare from a picture using GIMP. I am a beginner in GIMP and I tried using the healing tool and cloning but neither seems to work well but I may be doing this wrong. I also have a similar picture where I don't have the glare as bad and I was trying to clone using this picture but it doesn't look natural. I have glasses glare in a lot of pictures so it'd be useful to know how to remove the glare for future use too.

Pic with glare: http://i64.tinypic.com/ztvn6u.jpg
Pic without glare: http://i63.tinypic.com/wv7amg.jpg