1. Locate the hydraulic oil filter. This will be located along the side of the tractor or in the engine compartment, depending on the model.
2. Drain the hydraulic oil into a suitable container for disposal, and replace the oil filter.
3. Bleed the system by removing the lower and then the upper line from the oil filter housing.
4. Refill the hydraulic oil tank and install the new oil filter.
5. Prime the filter by filling it with oil from above and allow it to flow through the filter until it comes back out.
6. Replace the upper and lower lines to the filter housing.
7. Prime the system by operating the tractor. This should be done with the tractor sitting on level ground and all controls at the neutral position.