I got this tool, but I was not successful in loosening the bolts. I soaked them again with PB blaster and will use some heat for the next attempt.Use an Impact screw driver with the Allen bit. Not a pneumatic driver, a hammer impact driver.
Just an example TEKTON 2905 3/8-Inch Drive Manual Hand Impact Driver Set, 7-Piece - Screwdriver Bit Sets - Amazon.com
Also, when you re-assemble, use Never-seize on the threads for the aluminum block.