How do you release locally (offline) with git ?

Execute Maven release:prepare goal

mvn release:prepare -DpushChanges=false -DremoteTagging=false

• pushChanges parameter allows pushing changes using the local instead the upstream repository.
• remotingTagging parameter doesn’t explicit in release plugin document, but prevents the duplicate tagging while you need execute prepare goal once again after failure.

Execute Maven release:perform goal

mvn release:perform -DlocalCheckout=true

The localCheckout parameter allows using a local checkout instead of doing a checkout from the upstream repository.

How do you clean project folder ?

Use Git with command clean.

git clean -xdf

This command removes all untracked files.