Modification in Shift timings - requirement of written permission from the Chief Inspector of Factories/Labour department?

In our factory shift timing starts: A. shift 6.00 am to 2.00 pm; B. shift 2.00 pm to 10.00 pm & C. shift 10.00 pm to 6.00 am this includes 30 minutes Lunch/Rest time. It means total work our is 7.30 hrs + 30 minutes Lunch/Rest. Now our Management has decided to change shift timing i.e. 8.00 hours work + 30 minutes Lunch/Rest time.
Please suggest us as to how can it be modified & what will be the new shift timing. Is there any requirement of written permission from the Chief Inspector of Factories/Labour department?

Kindly refer section 61 Of factories Act in this connection
Some extracts for info:
Any proposed change in the system of work in any factory which will necessitate a change in the notice referred to in sub-section (1) shall be notified to the Inspector in duplicate before the change is made, and except with the previous sanction of the Inspector, no such change shall be made until one week has elapsed since the last change. tc "(10) Any proposed change in the system of work in any factory which will necessitate a change in the notice referred to in sub-section (1) shall be notified to the Inspector in duplicate before the change is made, and except with the previous sanction of the Inspector, no such change shall be made until one week has elapsed since the last change."