To operate with x-axis, y-axis, or u-axis motors you must remove the x-axis and y-axis motors or u-axis and y-axis motors in pairs as a frame connects them for higher stability.
To get access to the horizontal movement motor mount screws you must remove the lid first. Step-by-step instructions are here.
Also, you need to remove the belts connected to the corresponding motors.
Important: Power Off the machine before this manipulations and unplug the cord from the mains.
Tools: Hex 2.5 mm driver, wrench 7 mm (m4).
Be careful with the last bolt - do not let motors fall after bolt removal - it can damage equipment.