Step 7: Cut the mounting plate down to size
Allow about 3mm between the outer holes in the mounting plate and the outer edges (using 2mm holes, this gives 2mm of metal on the outside. You may find you need more.). Trim the top and bottom edges so the whole thing is about 7 or 8mm high. If using self tapping screws, screw them into the mounting holes now so you are not straining the assembly when you assemble it, and then remove them. Ensure there are no stray bits of metal attached to the plate.