hot air gun is for professionals only. you warp or deformed the glass casing if you applied so hot air on it. if you haven't use one before then don't. there many kinds of heat power for this tools i suggest you use hot air gun with low wattage a little hotter than hair dyer. try the low setting first. but first before doing it. i suggest buy on ebay where LCD digitize r and front casing are sold together its brand new and much safer or look for someone who are selling their nexus 7 with a broken motherboard.