How to Uninstall the Agent Oracle Home that registered with inventory

A long title for a short trick. I have uninstalled my cloud control agent and tried to re-install it. I gave the same directory I previously used to install and EM Cloud Control Agent Deploy Wizard gave an error at remote prerequisite check:

So it says I should deploy to a different directory or uninstall the Agent Oracle Home already registered. Because of our deployment standards, I need to deploy this agent to the same directory so I searched how I can uninstall the Agent Oracle Home.

Agent Homes are stored in /etc/oragchomelist (Linux) and /var/opt/oracle/oragchomelist (Solaris). I removed the entry from oragchomelist and retry to deploy and I got the same error! Then I checked the Oracle Inventory file - its location can be found at /var/opt/oracle/oraInst.loc (Solaris), the inventory file (ContentsXML/inventory.xml) has some entries for the Agent Homes:

<HOME NAME="agent12g2" LOC="/oracle/cloud/core/12.1.0.1.0" TYPE="O" IDX="13">
<REFHOMELIST>
 <REFHOME LOC="/oracle/cloud/...discovery.plugin_12
.1.0.1.0"/>
 <REFHOME LOC="/oracle/cloud/...discovery.plugin_12.1
.0.1.0"/>
 <REFHOME LOC="/oracle/cloud/...discovery.plugin_12.1
.0.1.0"/>
 <REFHOME LOC="/oracle/cloud/...discovery.plugin_12.1
.0.1.0"/>
 <REFHOME LOC="/oracle/cloud/plugins/oracle.sysman.oh.agent.plugin_12.1.0.1
.0"/>
</REFHOMELIST>
</HOME>

Because I have already a working Oracle Database at this server, I didn't delete the oraInventory files, and I issued the following command to detach the Agent Home:

$ORACLE_HOME/oui/bin/runInstaller -silent -detachHome
ORACLE_HOME="/oracle/cloud/core/12.1.0.1.0"

That's it. I re-run the deployment agent and it completed without any error.