[Koha] converting existing serial subscriptions from "no items" to "generate items"

[Giuseppe Angilella]

Hi,

whenever one creates a new subscription for a serial, Koha prompts whether 
you would like to "create an item record when receiving this serial", or 
not.

Now, after some experience with my patrons, it seems that the best way of 
keeping track of serial loans is to have items for each serial issue.

Therefore, I need to edit existing subscriptions, so that a new item 
record is created whenever a new serial issue is received. But how do I 
attach items to serial issues already recorded?

(Do I need to delete them all, and start "receiving" existing issues as if 
they were new? I understand that unavoidably there might be some "manual" 
work to be done, but I would like to save as many as possible of the 
details already entered in the database.)

Many thanks in advance and best regards,

Giuseppe.