Editing S7 instance data blocks assigned to fb

All im a little stuck I have a FB1 that has 2 instance data blocks assigned to it DB1 and DB2, what I want to do is edit DB1 assignment to a different FB2 and remove the assignment of that DB1 from FB1.
I cannot find this out anywhere when I open up the object properties for the FB1 or DB1 you cannot make any changes to the DB assignments
Thanks for any help

Just delete the DB that you no longer want to use with FB1 (in Simatic Manager) then create a new DB - with the same name as the old one if you want - (Insert -> S7-Block) declared as an Instance-DB for FB2.

Thanks for that, I guess I was thinking there would be a way to just edit this in the object properties but that would be to easy for siemens to do!