I bought this sigma 150-500 for my Nikon D5300 through website. But when I attached it on my camera I noticed that VR (vibration reduction is not working. After some research on internet I came to know that firmware of lens is not supported.and sigma company is offering free firmware upgrade. But would not be possible for me right now. I want to know if there is any other way that I can make my lens work on d5300. Any modification on circuit board of lens can be managed. Anyone who can guide me . I think some looping on circuit board must be there and possible. Please guide and help.

Cameras - Sigma - 150-500/5.0-6.3 DG OS APO HSM Nikon