Hi,
Rename you .apk to .zip file.
Extract the .apk file. you will find the .so file under lib directory
Create a directory called "lib" under your you app.
Copy all .so file into your app/lib directory.
Then create a android make file under your you app.
Use the variable LOCAL_PREBUILT_LIBS to make an entry of all your .so
file.
Use the sample make file:
---------------------------------------------------
LOCAL_PATH := $(my-dir)
include $(CLEAR_VARS)
LOCAL_PREBUILT_LIBS := \
lib\libone.so \
lib\libtwo.so \
lib\libThree.so
include $(BUILD_MULTI_PREBUILT)
----------------------------------------------------------
This will places all your .so file in /system/lib/
For more info refer the link:
http://source.android.com/porting/build_cookbook.html
~br,
raghu