You will need: a 17 mm wrench…
…a special key for brake pipes "for 10".
1. Remove the battery mounting shelf (see "Removing and installing the battery mounting shelf").
2. Loosen the nuts securing the two pipes to the brake force regulators, holding the regulators from turning with a second wrench, and move the pipes to the side.
3. Loosen the pressure regulator...
4. …and unscrew the regulator from the main brake cylinder housing.
5. Remove the second pressure regulator in the same way.
NOTE: Pay attention to the markings on the regulators. Install regulators with exactly the same markings.
6. Install the pressure regulators in the reverse order of removal and bleed the air from the brake system hydraulic drive (see "Bleeding the hydraulic brake system").