Substances the Calm the Spirit

What special cooking instruction should be followed when preparing Suan Zao Ren (ziziphi spinoase semen) in decoction?

Suan Zao Ren has a hard shell, so it must be crushed in order to extract its medicinal ingredients.

Source: Bensky, D. (2004). Chinese Herbal Medicine: Materia Medica. Seattle, WA: Eastland Press. pp. 928 [Q1175]