To replace the blade, proceed as follows-- Block axial movement of the cutting head by means of the handwheels. Disassemble the front guard. Loosen the locknut by rotating clockwise left thread, using a 19 mm wrench. Move the cutting head forward slightly and incline to remove the blade from its seat. Ensure that there are no foreign objects between the fixing flange and diamond blade. During disassembly, avoid use of tools that could dent or deform the flange. Insert the new blade proceeding in reverse order of the operation described at point 4. Take special care to ensure correct direction ofrotation of the diamond blade. Tighten the blade locknut fully down by rotating anticlockwise left thread, to a torque of 40 Nm.