Ok, Charizard, lift yourself into the air(and try to blow a safe spot open for one of your partners) and fire a blast of Flamethrower into Skarmory. If he attemps an attack, try a Fireblast as soon as it gets close. Next, Soar up a bit and Body Slam onto Skarmory!! If it tries to move out of range, Fire-Spin it instead!! Finally, if you slammed it into the glass with Body Slam, fly over to a safe spot and set up a Reflect. If Fire Spin was used, then most of the glass is probably melted into a bunch of jagged spikes. Scary Face, and lower it's speed, and maybe startle it onto the spikes below!!