Migrating from blogger, a guide

As for the details, here is what I did.

Blogger Settings Changes

• Under Settings -> Formatting, make sure your Timestamp setting is MM/DD/YYYY HH:MM:SS AM/PM format. 
• Also under Settings -> Formatting, don't change the "convert linebreaks" value from whatever you have set. This goes against other instructions.
• Under Settings -> Comments, make sure your Timestamp setting is MM/DD/YYYY HH:MM:SS AM/PM format.
  
• Under Settings -> Archive, set Archive Frequency to 'Monthly', and "post pages" to off (this'll save time on the publish)
• Under Settings -> Archive, either change the value of "Archive Filename" or change the "Archive Path". Either will work.

Blogger Template Change
First and foremost, go to Template and save your template somewhere safe.
Second, change your template to this:

<blogger><ArchivePage>
EAUTHOR:::yourmtusername
ETITLE:::<PostSubject><$BlogItemSubject$></PostSubject>
EDATE:::<$BlogItemDateTime$>
EBODY:::<$BlogItemBody$>
<BlogItemComments>
CAUTHOR:::<$BlogCommentAuthor$>
CDATE:::<$BlogCommentDateTime$>
CBODY:::<$BlogCommentBody$>
</blogitemcomments>
</ArchivePage></Blogger>

Change the value of "EAUTHOR" to whatever you've named your username in Movable Type. This way when everything imports, it'll all belong to the correct user in MT.

What this is doing is exporting your blog into a custom format. This is the format needed by the script.

Publish the blog
Do a Publish All on your blog. This will update your Archive data.

Gain access to the Archive data
SSH into your web-server, or ftp down the archive data. Whichever. However you do it, grab the files that were published in the previous step into an area you can process them with the perl script.

Run the script against the files
The command is very simple:

perl blogger2mt.pl infile outfile

If you are doing this on the web-server, this could easily look like this:

perl blogger2mt.pl ~/public_html/blog/archive/2010_01_01_export.txt ~/public_html/cgi-bin/mt/import/2010_01_01_export.txt

This is scriptable.
for file in *.txt; do perl ~/bin/blogger2mt.pl $file ~/public_html/cgi-bin/mt/import/$file; done

The output will be Movable Type formatted Export files.

Import the entries
You would be wise to try this on a single file first, rather than doing it all at once without trial.  This can underline faults in your template that you can fix without having to republish umpty thousand entries like me.You have been warned.

1. Log in to MT as an Admin
   
2. Go to your Blog
3. Go to Tools
4. Select Import
5. The default values should be good
6. Click Import
7. Review the results page, you should see imported entries, categories (labels in Blogger parlance), and comments.
   
8. Go to your Entries page to see what is there.
9. Select-All, then click Publish to make it so.

With luck, you now have your Blogger blog imported, complete with entries, labels, and comments!