Step 1: Verify System Requirements
Before beginning, it's crucial to ensure your ESXi host meets the minimum system requirements for Pam360. These requirements depend on the number of devices and accounts you plan to manage with Pam360. For a medium-sized deployment, for example, you might need:

- 4 vCPUs (or more, based on workload)
- 8 GB RAM (minimum)
- 200 GB storage (SSD recommended for better performance)
 
Consult the latest Pam360 documentation for specific requirements tailored to your deployment size.

Step 2: Download Pam360 OVA File
1. Visit the ManageEngine official website.
2. Navigate to the Pam360 download section and select the version designed for VMware (OVA file).
3. Click on the download link and save the file to an accessible location on your computer.

Step 3: Log in to your ESXi Web Interface
1. Open a web browser and type in the IP address of your ESXi host.
2. Enter your username and password to access the ESXi dashboard.

Step 4: Deploy the Pam360 Virtual Appliance
1. In the ESXi dashboard, navigate to "Virtual Machines" and select "Create / Register VM."
2. Choose "Deploy a virtual machine from an OVF or OVA file" and click "Next."
3. Assign a name to your Pam360 VM that easily identifies it among other VMs.
4. Click "Click to select files or drag/drop" and upload the OVA file you downloaded in Step 2.
5. Follow the prompts to select the storage for your VM. Choose a datastore with enough space and good performance characteristics.
6. Configure the network settings for your VM, selecting the appropriate network for Pam360 to communicate within your infrastructure.

Step 5: Customize Virtual Machine Settings (Optional)
1. After deploying the OVA, you may adjust the VM's settings to better fit your environment. Right-click on the Pam360 VM and select "Edit Settings."
2. Here, you can allocate more CPU or RAM to the VM if you anticipate a high workload. Adjustments should align with the system requirements and your performance expectations.

Step 6: Power On the Pam360 VM
1. Right-click on the Pam360 VM in the list of virtual machines and select "Power On."
2. Wait for the VM to fully boot up. This process might take several minutes.

Step 7: Access the Pam360 Application
1. Once the VM is running, open a console window in the ESXi interface to view the VM's display. It will show the initial setup information, including the IP address assigned to the VM.
2. Note the IP address displayed in the console window.
3. Open a web browser on another computer and navigate to the noted IP address. This opens the Pam360 web interface, indicating the application is ready for setup.

Step 8: Complete the Pam360 Setup
1. The initial access to the Pam360 web interface will launch the setup wizard. Here, you will configure essential settings like the database configuration (embedded or external) and network settings.
2. Create an admin account for Pam360. This account will be used for all subsequent logins to the Pam360 interface.
3. Complete the wizard steps, adjusting settings as necessary for your environment.

Step 9: Verify Installation
1. Explore the Pam360 dashboard to familiarize yourself with its features and ensure it's operating correctly.
2. Test adding a few devices or accounts to verify that Pam360 can communicate with and manage them as expected.

Step 10: Backup and Security
- Set up regular backups for your Pam360 VM through the ESXi interface. This is crucial for disaster recovery.
- Implement security best practices, such as configuring firewalls and ensuring the VM is only accessible from secure networks.

Remember, this guide provides a general overview. You should consult the official ManageEngine Pam360 documentation for detailed instructions, including troubleshooting tips and advanced configurations. Additionally, keep your ESXi host and Pam360 application updated to benefit from the latest features and security patches.