Once the template is created, you can also make any changes to an existing template as needed. There could be requirements in future to add new components / tweak the existing structure in the template. In such cases, you can edit the template and make the necessary changes.
To edit an existing PDP template:
Click the Edit Template
icon in the Action column next to the template to be edited and the following is displayed.

The existing structure as present in the selected template is displayed. As mentioned in section Creating a PDP Template, you can drag and drop components as needed to add them to the structure as well as remove any component and make changes in the dimensions, settings and so on.
For example, let us add related SKUs in the structure which is an PCC component to display all the SKUs which are related to the SKU that will be selected for viewing using this PDP.
Drag and drop the container within which you can drag and drop the Related SKUs PCC component as shown below.

Click Next to map the entities added. However, in this case, since related SKUs are added, they are automatically mapped as the related SKUs will be displayed based on the SKU selected for viewing as shown below.

Click Next and the following screen to save the changes is displayed.

Since this is an existing template, the name of the template is already saved. You can change the name of the template as well as preview the template using sample data as explained in steps 12 to 15 in section Creating a PDP Template.
Click Submit once the structure is finalized and the PDP template is updated.