Grab the source code from the article and place copy the genmembership\llbl\tasks ans genmembership\llbl\templates folders into some place you can use later, like *C:\Dev\LLBLGen\AdditionalTasksAndTemplates*
Open your v3.x LLBLGen project you want to use. Then go to Project->Settings->General, there change the following settings:
Now go to Tools->Refresh Code Generation Metadata. This will update the template system to include the newly additional tasks and templates.
Click [F7] (Generate Code). On the "Selected Preset" field, choose the Custom.EntityFramework.v4(...) and click on "Start generator". This will create the repository files.