Problem with extension in HiJazz tutorial

Hi everyone,
I'm following step-by-step tutorial on developing a jazz plugin here.
I've set up my RTC as stated here.
I select and add com.ibm.team.repository.common.components extension point then, when I'm not asked to fill component details on the right but it ask me simply to "set the properties of selected extension " (not component) and both filelds are not required.
So then when I create my interface and right-click on the extension point I'm not asked for service but simply for general.
So I can't go any further following the tutorial.
Am I missing something?
Thank you.