There's no simple way. An email won't work and you are expected to fax or snail mail the complaint document with your Signature to Google Headquarters in CA.
[Infact, it's much easier deal with content thieves when their site is hosted outside Blogger.com. Read this - Options when someone copies an article from your blog]
Here's an excerpt of the email that I received from the Blogger team when I reported a Blogspot blog which was regularly copying content from this site verbatim.
To file a notice of infringement with us, you must provide a written communication (by fax or regular mail, not by email) that sets forth the items specified below.
Please note that pursuant to that Act, you may be liable to the alleged infringer for damages (including costs and attorneys' fees) if you materially misrepresent that you own an item when you in fact do not.
Indeed, in a recent case, a company that sent an infringement notification seeking removal of online materials that were protected by the fair use doctrine was ordered to pay such costs and attorneys fees. The company agreed to pay over $100,000. Accordingly, if you are not sure whether material available online infringes your copyright, we suggest that you first contact an attorney.
To expedite our ability to process your request, please use the following format (including section numbers):
1. Identify in sufficient detail the copyrighted work that you believe has been infringed upon. This must include identification of specific posts, as opposed to entire sites. Posts must be referenced by either the dates in which they appear or the permalink of the post.
2. Identify the material that you claim is infringing upon the copyrighted work listed in item #1 above.
YOU MUST IDENTIFY EACH POST BY PERMALINK OR DATE THAT ALLEGEDLY CONTAINS INFRINGING MATERIAL. The permalink for a post is usually found by clicking on the timestamp of the post.
3. Provide information reasonably sufficient to permit Blogger to contact you (email address is preferred).
4. Include the following statement: "I have a good faith belief that use of the copyrighted materials described above on the allegedly infringing web pages is not authorized by the copyright owner, its agent, or the law."
5. Include the following statement: "I swear, under penalty of perjury, that the information in the notification is accurate and that I am the copyright owner or am authorized to act on behalf of the owner of an exclusive right that is allegedly infringed."
6. Sign the paper.
7. Send the written communication to the following address:
Google, Inc.
Attn: Blogger Legal Support, DMCA complaints
1600 Amphitheatre Pkwy
Mountain View, CA 94043
OR Fax to:
(650) 618-2680, Attn: Blogger Legal Support, DMCA complaints
Sincerely,
The Blogger Team
How to Contact Blogspot Staff - Important Blogger.com URLs that you may not be aware of.