Go to:
C:\Users\<username>\AppData\Roaming\Windows Live Writer\blogtemplates\<id>\
There should be 2 files in this folder.
The one that is smaller in size is the template we use when you are in edit mode. The one larger in size is the one we use when in preview mode. If your preview mode is also broken you will need to edit that as well, otherwise you really only need to edit the 'edit mode' file.
When you open it up, you will notice it is just a normal HTML file. There are 2 important tokens that we add to it though:
{post-title} and {post-body}, you will just have to edit the HTML around them to put them in the correct place. As you editing the file, you should be able to view it in any browser, you don't have to open up WLW to verify it is working.
Once you are done, you should be good to go.
If you run into any problems let me know at
bturner@microsoft.com
-Brandon Turner [MSFT]