Runtime change not compiled

Hi, I have made some small changes to some files in the Runtime environment, however it looks like these are not applied nor compiled by default. My changes in plugins and so on compile on glance.
I am very new to Eclipse, so probably I am missing something simple. Please let me how to recompile the Runtime.

Thanks
Thomas

Hi, anybody out there, it would be very nice if some could give me a small hint. Again: I tried to change a Java source file in the Runtime tree but it looks like these changes are not compiled into. I use the latest Eclipse environment with fully checkout of all sources (runtime + plugins). Changes in the plugins are built and visible without problems.