How do I migrate Lync Server 2013 correctly?

Question

System administration

Good day to all!
A small preface:
Recently, the responsibility for maintaining the Lync 2013 server was transferred to me, I will say right away that I have been working in administration recently and I am not familiar with the intricacies of installing and configuring this server.
Now the essence:
The company has several branches located in different cities. It was decided to combine two of them in one place. Deployed on Lync 2013 server in two cities: LYNC01-1, LYNC01-2; with its own user base, the servers are combined into a topology. There are several options for the development of events:
1. Deploy a new server on the new site, then transfer all users to it.
2. Transfer one of the servers to a new site, transfer users from another site, make settings in the topology.
3. Deploy a new server on the new site, add it to the existing topology, and perform transfer actions within the topology.
In addition, there are 2 more servers in the topology that remain in their places. The total number of servers in the topology is currently 4, after the move there should be 3 (this is in theory).
There are also LyncEdge servers that will also be migrated.
Which of the events is correct? Are there any other ways to transfer the server? How might renaming and moving an existing server to a different subnet (this applies to option 2) affect performance? Are there any other points to consider?
UPD. Since I inherited the server data from an engineer who got a promotion, I had to dig a little theory and look at the settings. It turned out that the topology deployed:
1) 4 sites (according to the number of branches)
2) Standard Front End pool deployed on each site
3) Edge Server, Reverse Proxy, Web App Server deployed on the main site
4) Monitoring and archiving deployed on a separate SQLServer , which is different for each FE
5) There is no integration into telephony, there are no PSTN gateways and Mediation servers

Answer 1

Transferring and even more so renaming the server is definitely not worth it. Of course, I did not try to try, but even theoretically it will not end in anything good.
As far as I understand, each branch has its own Standard FE or SBA.
In this case, the most correct and problem-free option is to deploy a new server and transfer everyone to it. Of course, for this you will have to add it to the topology. There shouldn't be any problems, unless of course all users are in the same domain.
In such cases, it will also be possible to simply rebind the PSTN gateways to the new Mediation server and you will not have to do any more settings on Lync.

Answer 2

In general, option number 1 was chosen.
1) Prepare a topology with the inclusion of a new site, then publish this topology
2) Set up a new Link server (deployment of services and components)
3) Migrate users to a new node.
4) Now the Edge and Reverse Proxy servers are being deployed (access from the external network and for mobile clients, respectively)
Since Link does not have telephony integration, PSTN gateways and Mediation servers are not deployed.
Further plans are to transfer the Topology Administration Server to the newly deployed server.