Hi, Can I change default themes of my blogspot blog and install any stylish themes like wordpress themes?
Well, changing default blogger template into the new ones is very simple and there hundreds of articles telling you how to change it. Just googling and type " Change blogger template"
There are tons of free Blogger templates available online, you just need to know where to look. One of the most common is http://www.btemplates.com/, I would suggest starting there and seeing what you can find.
http://www.bloggertemplates.org/faq/how-to-change-your-blogger-template http://blogger-templates.blogspot.com/2004/04/change-blogger-template.html step by step guide. hope this will help you.
You can change your blogger theme with other blogger templates. Here's how to do it without losing widgets and stuff you've already added to your site http://www.learntoearn101.net/2009/07/how-to-change-blogger-template-without.html