Simplebim templates can be either installed or you can apply them directly from the file system.
When you install a template you can easily access it from the Simplebim user interface. Installing templates also enables template chaining.
Installed templates can be applied from the Simplebim startup screen by clicking on the template in the 'IFC Import' section. This allows you to import an IFC file and apply the template to it as one operation.
Once you have opened or imported a model you can apply a installed template to it from the 'Apply Template' button in the ribbon. Click the lower part of the button and navigate to the template you wish to apply.
Templates can be applied directly from a template file (Excel file) after you have imported or opened a model.
Click on the upper half of the 'Apply Template' button or select 'Browse (default)' from the dropdown menu.
This opens a File Open dialog that you can use for selecting your template file from anywhere on your computer.