It’s very easy to change from a Google template to another and have everything work: simply go to Customize, and select Choose New Template and Blogger offers you variations of about a dozen original formats, usually in multiple color variations.
However, there are many well-designed and more professional looking templates out there, very tempting for the everyday blogger to import. Most of these are tested for blogger and work fine, but Google has made the importation of these a buggy and more tedious process than it used to be.
There are simple steps to make these other templates work.
1. To change to a new template, you must first have the new one downloaded onto your local computer, and it will normally be in .XML format, but sometimes is simply in a TXT file.
2. Inside of Blogger, select Customize your blog.
3. First backup the existing template: select Layout, Edit HTML and Download Template. Change the name to something you recognize, like 'Temp-MyBlog-030509', then save it. This takes a few seconds, the file will be small, usually 50-100k. This will not save the posts, that's next.
4. Next, backup your posts. You won't have to reload them, it's just a good idea to back them up before major changes. Select Settings, then Export Blog (the Basic tab). This exports the posts themselves. Again save the file as something you remember, like 'Exp-MyBlog-030509'.
5. You need to back up or copy each of your widgets HTML code. Make sure you use a text editor like Notepad. I put them all in one file with labels for each and a seperator line, which makes it easy to copy them back into the new template. Unfortunately, copy and paste is the only method you can use here, one at a time, so it can be tedious with a crowded interface with lots of sidebar gadgets.
6. Now you’re ready for the new template. Return to Edit HTML, and select Browse to find the new template on your computer. When you select it, hit Ok, then when back in Blogger, select Upload. The new template will be transferred to Blogger.
7. After the refresh, you will see a list of widgets on the left that will be deleted, such as 'html1' and 'blog1'. If you proceed from here, you will likely get the infamous 'Bk-#' error screen with an error code. You must first debug the new template.
8. Use 'Ctrl-F' to Find, and search for 'widget id'.
9. When you find one, edit the resulting name you see by incrementing the number, as in 'html1' should become 'html2', 'text1' becomes 'text2', and so on. There may be two or more of each of these, change them all. Don’t miss changing 'blog1' to 'blog2', this is almost always present.
10. When you’ve edited them all (and be careful to NOT cycle through them twice), click Save Template. After the screen refreshes, you have a new list of widgets that will be deleted, but now it’s OK, none will be from the new template.
11. Click Confirm and Save. This should work without errors now, and you can select either Preview or View Blog and see the results.
12. You can now copy your widgets back (one at a time) that were deleted during the importation process. Even if you have many, it should take less than an hour.
Since you’ve properly backed up the previous template, if there’s a problem with the new one or you don’t like it, you can change back to the original by using the upload process again, and select the original template backup name. You will have to copy back the original widgets again, but at least you won’t lose anything.
Build at test blog first, then don’t be afraid to try a new template to refresh your blog!
Note: This blog is currently using a variation of Froggy, without the frogs, from Our Blog Templates, see the footer at the bottom.