How to fit this schematic into my circuit
A and B go to the bridge, Vo is the output (relative to ground, or to the right-hand side of R2 if that point is not grounded).
The resistor values shown are rather low, I would suggest 10K or 20K. Rg will be determined from your desired gain. I'm not sure what the '745' op-amp is. If it's an AD745, there are probably better/cheaper choices.