I tried the Dremel tool. I felt there was too much risk of making a cut into the lens material that could compromise the re-seal. I found it easy to melt the plastic even at low RPMS, break discs and there were several areas that are not straight enough to use the cut length of a disc that was effective.

I wouldn't say not to use the tool since I seldom use the Dremel putting me in the category of at best a clumsy rookie.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas