would like to know the best way to drain ac sys to change the compresser on 2000 Dodge Caravan

we'll be working on with minamul tools please help

2 answers
In addition to the first comment, if the compressor is noisy or locked up, you will need to flush the system and install a filter on the low pressure side before the compressor to prevent debris in the system from damaging the new compressor.
you need a recovery machine and ability to vacuum it out when done. you also need a dryer and an expansion valve if the compressor locked up.

Roy