4xM3 4mm or 6 mm screws, preferable flat point set screws to lock the x-axis rods.
2xM3 12mm to adjust the x-axis up/down
For the assembly follow the original model.
CHANGELOG
V5: Add cut outs to remove the square nuts and move the flat point holes to the front. This allows to adjust the belt or skew without unmounting the x-End from the rail all the time.
V4: Add cut out (windows) to see the rod and the screw adjustment.
V3: Add holes for flat point screws to lock the rods, avoiding the printer to skew.