Oilchange, how to ?

[Challenger]

Hi, I need to change oil on a Bitzer provision compressor. Model 4G-20.2Y-40P

Can anyone in here please check if this is the right way to do it. If not please correct me..

Thanks.........

1. Close suction valve and wait untill compressor stops.

2. Turn off compressor

3. Close outlet valve from compressor.

4. Open valve marked C on attached picture.

5. Drain old oil through C

6. Fill oil through C with a handpump.

7. Cloce valve C

8. Connect vacuum pump to compressor outlet valve.

9. Turn on pump and pump out moisture in compressor.

10. After this open suction valve and start compressor.

Can it be done like this ?

What is A and B on the picture ?