The dry ice method you mention is more easily accompished using a product such as Freeze in a can. That combined with the rat-a-tat-tat of a drill or impact wrench on a low setting has much merit in my opinion.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)