Hello,
1. in some cases need to open phone to find Rx/Tx/Gnd points becaause some phones don't have Rx/Tx/Gnd on bottom connector.
2. and 3.: Please, read this:
http://www./showthread.php?t=476373
You will see information about cables, pinouts, repair procedures etc.
4. battery should be in phone
If you will have more questions don't hesitate to ask your exact questions and we will give you an advice.