Copy fields from WorkOrder to Account

After an WorkOrder is executed (post or canceled) I need to copy several custom fields filled in during the WorkOrder execution, to similar fields of ServuceAccount associated with the WorkOrder.

For example, when an WorkOrder is created I can copy info from Account to WorkOrder by using Customization, Account, 1:N Relashionships, Mappings.

So, how can I do the opposite?

Thank you,

Ionut