I have done this with good success. I use a hammer to drive a socket of the appropriate size over the outside of the bolt head. Then simply remove the bolt. You must then pound the bolt out of the socket. Sometimes you need to use a SAE size on the metric allen head bolts.

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I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k