• First close the miner by pressing CTRL+C only once
• Rename the "steem" folder to "steem-old"
• Then you can just repeat the same build operations you did with your current miner or use this https://steemit.com/steem/@pfunk/guide-maximize-your-mining-hashrate-in-windows-by-mining-steem-in-a-vm
• copy "witness_node_data_dir" from your "steem-old" to your new
  "steem/programs/steemd" directory
• then start your miner

That should do it.