Updating Related Records

Updating Related Records

Hi, 

Im looking at creating a button or a blueprint function, that when selected it will change the status off all assocated records within a particular related record section for example.

Sales Order Module
Payment Status is changed to Refunded
Related Records Module is Services
Update Services record(s) to Paused

How would the best way of getting this done, Ive tried custom functions but am just going around in circles. 

Thanks