Step 1: Login Dell Boomi Platform using the below link
https://platform.boomi.com/#login
 Step 2: Go to the Deploy tab as shown below

Step 3: Select the process to be undeployed as shown below:

Step 4: Go to the attachments tab and select the attached environment from where we need to undeploy the process

Step 5:Move the attached environment to unattached environments.

Step 6: Go back to deployments and the process gets undeployed.