This article will describe the steps required to apply a Dreamweaver Template to multiple files at once.
STEP BY STEP
Select all the files in the File Explorer on which the template needs to be applied.
Perform a Find and Replace on the Selected Files and in the source find the <old-template>.dwt text and replace that with <new-template>.dwt. This will mark all the selected files to have the <new-template>.dwt template.
Go to Modify, Templates and Update Pages. Select Template to update all the recently modified web pages to be updated with the <new-template>.dwt.
Use the same logic to update Library items across multiple files.
This strategy works best in organized websites which have a symmetrical system implemented. For example, having all English files named at filename.html and their French counterparts as filename.fr.html, this convention should be used for all files in the webroot, including images, templates, library items, etc.