Can't instal "web part restriction according to roles" module

I'm developing site under CMS Kentico v7. I need to add web part permission module. I'm instaling it according to this article. There are two problems:

1. After adding two lines to code (step 2 and 3 in article above) Visual Studio underlining WebPartPermissionMethods and prints "The name WebPartPermissionMethods does not exist in current context". Shouldn't I add another using at the begining of code?
2. In step 4 trget url should be set to "~/CMSModules/WebPartPermission/Default.aspx". But such a file dosen't exist.