Consolidate 2 BW system in a single System

Hi Expert,

I have a requirement to consolidate 2 BW system and keep only single BW system.

EXP. BW1 and BW2 systems are there. Now we need to bring all the BW1 system objects in BW2 system. what is the best possible solution to do it with minimal effort estimation.

1) Develop all BW1 objects in BW2 system?

2) Transport all the BW1 Objects in to BW2 and test it

3) Refresh BW2 system with BW1 system without impecting any existing BW2 objects (if posible) and do the regression test.

Please share your input if anyone have faced same scenario

Cheers

Anil