That is easy to find the blog manage entrance. As long as you login website with the blog owner account, you will obviously find the manage links in your blog page. There should exist 4 links with which you can enter the manage page for your blog management. If you can not find those links, maybe you had not been authorized as a standard "SunBlogNuke Owner" role yet. Please contact your dnn admin for more details. Take a look at the screenshot:

The blog manage entrances for SunBlogNuke