To replace the rollers on a Honda SH 125, first open the cover on the left side of the engine. You will need to unscrew all the bolts around the perimeter of the cover, including the two central ones and the three that secure the plastic cover at the variator. Once all the bolts are removed, the cover will come off easily, giving you access to the transmission group and the variator. To remove the variator, unscrew the nut that secures it to the crankshaft; this can be done manually with a variator lock tool designed for this purpose or more simply using a pneumatic gun. After removing the nut, proceed to extract the fixed pulley from its seat, which will give access to the belt that can be released by manually widening the torque converters (rear pulleys) on the clutch side. Once the belt is out of the way, you can remove the variator body from the crankshaft, which consists of the central hub, the movable pulley, and the plate; by removing the plate, you will have access to the rollers that can be replaced with new ones. It is advisable to lubricate the rollers with a bit of grease before inserting them into their seat, and also pay particular attention to the type of rollers used, as some models have a specific insertion direction, so always check at the time of purchase. Once the new rollers are inserted, you can proceed to close the plate and reinsert the variator into its seat, reassembling everything in the reverse order of disassembly.