Install the two MGN12 3030 alignment tools as shown, this will make sure the linear rail is positioned correctly

Slide the MGN12 linear rail into the Y bumper printed part

Fasten the marked M3x12 screws, starting from the front.

MGN12 Rails should be tightened to 98 N-cm of torque, overtightening the screws will result in rail binging.

Remove the MGN12 3030 alignment tools

Repeat Steps 6 and 7 and install the linear rail on the opposite side