Query on Consolidation

I am facing a problem regarding consolidation in Navision Attain.The scenario is like that: A company has 4 different branches located at different locations and are using separate Navision Attain databases (Distributed environment). The head office is also using Navision Attain in it’s own location (it’s database is not connected with the branches).The head office want to integrate all the data coming from the different branches.In Navision Attain there is a facility called Consolidation(General Ledger->Periodic Activies->Consolidation). Can anyone pls. suggest me the exact procedure to do consolidation.