Questiom regarding replacing the lens

Hi! So the lens of my G11 has a scratch on the lens, I bought a replacement one, but saw it might need to be calibrated with software/it's not as easy as just replacing the mechanical part?

Can anyone who has any experience, please guide me as to:

1. How to proceed?
2. How to know if I can just replace the lens?
3. How to know what I would need to calibrate and what software would I need?

Thank you!