Need Help BW Installation

Hi

I would like to install BW7.0 on RHEL5 with oracle 10.2. I have following queries

1. Is it necessary to have JAVA+ABAP stack. If yes can both can be on same system.

2. How to install Java stack seperately 0r to install on abap stack individually

3. I will be happy if some one can share me installation docs or steps starting from OS installation.

4. How to pull the data from existing ecc6.0 / how to use data from an existing landscape

Thanks in advance