Android build prerequisites: 
download and install
- the Android SDK and
- the Android Eclipse plugin
from http://code.google.com/android

In Eclipse, 
- open menu File - New - Android Project,
- in New Android Project dialog select "Create project from existing source",
- browse to menstral/trunk
- click Finish

After this, you need to exclude from build these packages:
org.javia.lib.midp
org.menstral.midp
(because these packages contain MIDP-dependent classes, which don't compile on Android).

-- you can do this in Eclipse, in Package Explorer view, 
by selecting the respective package, and right-click "Build Path - Exclude".

Good luck!
Mihai