Splunk Migration from Site A to Site B (one data center to another)

[chimata1218]

Hi,

- We are currently having Splunk On-prem with single site (Site A) Version: 7.3.4 
   10 Indexers, 5 SH's, 2 DS, 2 HF's, CM, DMC, LM (Distributed Clustered)

- We have recently build another site  (Site B) Version 9.0.1
   10 Indexers, 4 SH's, 2 DS, 2 HF's, CM, DMC, LM (Distributed Clustered)

I have few below questions

How can we transfer/move the entire data from our Site A to our new site B?
What is the order to follow?
what are the Pre-Req's?
What would be the expected down time for this migration process?
is there any clear implementation documentation/steps?

Thanks in advance and your help would be highly appreciate!