It depends upon where your data is at. Are all assets, spaces, roles
and persons created or are you in the process of loading the data?
Regardless, if you want to automate this you will need some rules as
to which persons/roles and assets are to be matched up. For example,
if one person is going to be the contact/role for all assets, etc then
that makes the task a little easier. Once you know the rules then you
need to write workflows that (depending on where your data is) either
grabs the data as it's coming in (ie: Data Connect) or grabs the
records in the database (ie: using queries) and associates the records
accordingly. This is a fairly complicated exercise and not for the
novice. :)
Of course you will want to back up your data before doing anything.
\ken