Mostly it is sufficient to hang the garment for a while in fresh air.

The pores of the wool-hair open and impurities simply un-dock.

Wool rejuvenates naturally.

If it requires washing, I recomment the wool program of your washing machine, at a cold temperature (not over 30) with a good wool detergent. Do not spin over 600 rpm.

If possible dry the garment in a tumble dryer at the gentle / cooler setting. The tumble dryer restores the volume of the fabric.

Otherwise dry flat and shake the garment now and again during the drying process.