How to remove stripped allen bolt?????

[97GSX]

My fiends 97 GSX has a leak at the ehhaust manifold gasket, we tried to unbolt the manifold but the owner before him stripped the allen bolts on the carbs and on the manifold. What would be the best way to get these allen bolts out???? Could I JB weld a bolt to these allen bolts and use that as a turning point????? Any suggestion would be helpfull.
Thanks Chris

[1fastski.com]

drill the head of the bolt off , you will need a new one anyhow , then after you get the manifold off use vicegrips to remove the sutd . make sure the drill bit used is the same size as the bolt { not the head } that way as soon as your at the base os the head it will come off .