
I first started by removing the print surface and flipping the heat bed plate off toward the back of the printer. (not shown) There's no need to unhook it just be careful not to stress the wires. Raise the platform and remove the (3) M3 x 12mm screws that are holding the Spider to the Mounting Plate. (You can set the screws, springs, and spacers aside as they will no longer be used.) Next remove the rubber corners so you have a bare spider to work with.
Next you need to mark the location of the new leveling screws in the corner of each pad. With a pair of calipers I measured .4135 (10.50mm) from the outer side of each pad and mark a line. I then measure the same distance from the outer perpendicular side of each block and mark another line (you should have a plus at this point in between the two corner mounting holes.)
Then using a punch (or a nail) punch a mark in the center of the plus you made. (This little divot will keep the drill bit centered when you go to drill the hole.)
Next screw on a corner just to double check that your mark is in the correct location. (I am using Jim's Corners.) The mark should be right in the corner as shown.
The next step is to drill a hole through each pad of the spider. I highly recommend using a drill press for this. This hole will be tapped so you need to pick a bit that matches your tap. I chose to use 3mm hardware for this project so I used a #39 Bit. (NOTE - The standard Rev. E Leveing screws are larger than 3mm, but I'm not exactly sure what size they are.)