Cleaning android libExtensions build

Hi
After modifying some classes in extensions/spine, i can successfully compile on win32 but in eclipse for android, it fails with the following error:

make: *** No rule to make target `/cygdrive/d/cocos2d-x-2.1.5/Projects/RoosterFight/proj.android/../../../extensions/spine/Animation.cpp', needed by `obj/local/armeabi/objs/cocos_extension_static/spine/Animation.o'. Stop.

My guess is that i need to somehow clean the previous build of libExtensions but i don’t know how

Thanks!