Updating A Table Depending On 2 Databases

In a package we have statements pointing to 2(or more) different databases on the server. When moving between environments, is there an easy way to change statements like:

UPDATE t1
SET t1.name = t2.name,
t1.age = t2.age
FROM DB1..Person t1
INNER JOIN DB2..PersonToo t2
ON t1.PersonID = t2.PersonID

I can think only of building the statements replacing the database names with variables, but that's not an easy way. I do not know how to use package variables in this situation.
1 way of doing this may be by using a Lookup or Conditional Split and use the resulting dataflow in a SP or such to update, using parameters...
It all sounds very messy, and I still don't know how
Any ideas?


TIA,