Backup large blogger posts in small size
This tutorial is for those people who have very large Blogger posts in their Blogger account and they want to backup it in small sizes or in monthly backup format.The method which is used here is very complicated and long , the things required for doing large Blogger post backup in small sizes parts are
1.A WordPress self hosted account : (If you don’t have buy a cheap one , only requires for few days)
2.Any cheap domain (e.g. info domain)
3. Blogger Blog (Which is going to be backup)

Tutorial

Step 1.
Buy any cheap domain and assign it to your hosting account , and install WordPress software on it. If you don’t know about this there are several tutorials available on installing a domain on self hosted accounts.
Step 2.
Go the Blogger Blog > Settings > Language and formatting and see the time zone
and apply the same time zone settings in WordPress Blog by going to Settings > General see the screen shots
This step is important for permalink to work  accurately.

 Blogger time zone
WordPress time zone
Step 3.
In WordPress  go to Tools > Import >Click Blogger > install plugin and activate and run importer > click authorize
Grant access to WordPress and sign into your Blogger account. List of  Blogs will be shown select your Blog and click import.
WordPress blogger import
 Step 4.
Now you can backup posts in monthly small sizes parts
Go to WordPress Blog > Tools > Export >Select post >select date range and click download export file
make sure to select minimum range and backup file size shouldn’t exceed more than 5 MB. Rename each files with their desire Year and month.

 WordPress export post
Step 5.
Converting WordPress WXR Export file to Blogger XML
Open WordPress2Blogger Converter Tool  and choose exported WordPress files and click convert. This tool may not converts file bigger than 5 MB.

WordPress wxr to blogger xml
Converted file will be downloaded automatically make sure to rename file to originally as with year and month.
You have successfully  backup Blogger post in small sizes now you can restore them when you want , all permalinks will work as same as previously.