Pwr Steering--560SL

I'll soon be replacing the supply-side hose of the power steering. I noticed in the parts shop that a filter is listed for the power steering. Seems like a good time to change it as well. I have four questions:

1. Where is the filter located? I assume it would be somewhere on the return side form the steering gear. The CD-ROM manual doesn't show or mention the filter.

2. Should I try to drain all the fluid out of the system?

3. What do you recommend for power streeing fluid: ATF (brand?), or Power Steering Fluid (brand?)?

4. Although it looks like a straight forward procedure, are there any quirky things that I need to be aware of when replacing this hose?

Thanks in advance.

Bob Cavazos
'87 560SL