How to change the repository from server one to another?

hello ankit, please try this steps,

0: connect server 1 and server 2 in team artifacts view

1: go "pending change" view

2: right click your repository workspace

3: click "change flow target.."

4: click "repository.."

5: select other repository

6: deliver it.

There is no direct way of moving the Data from 1 server to another. Here are some considerations:

This Article has detailed Instructions on using Distributed SCM capability of RTC.

https://jazz.net/library/article/535/

For Work Items You can export them and then Import them to the new server using this article
https://jazz.net/wiki/bin/view/Main/BulkMoveWorkItemsBetweenProjectAreasInRTC4

For Process templates  for the PA , If you have custom ones, Simple use Export and Import Feature.
Thats first thing you would do for WI Import . So that a PA is created already in the second server identical to the other server where the WIs are exported from.

If you want to decommission the old server, then you are looking for "server rename".
Google will return a variety of articles that describe this functionality.
One of them is:  https://jazz.net/wiki/bin/view/Deployment/ServerRenameCLM401