Husqvarna TC 250 2010 Workshop Manual page 229

FRONT SUSPENSION
Take the cartridge out of the outer tube.
Do not remove the nut at the bottom end of the cartridge.
Remove the bottom valve assembly from the cartridge.
Hold the cartridge octagonal nut with the suitable tool to prevent rotation.
Use a similar tool in the octagonal recess of the bottom valve assembly.
Use a key to slacken the bottom valve assembly.
Check the O-rings on the bottom valve assembly for damage.
Replace as required.
I.9
Part. N. 8000 H1489 (10-2009)