You can reduce data in packages other than CASA, such as AIPS, Gipsy, or Miriad. First, get the data from the ALMA archive. It will be in the "ASDM" format. Read it into CASA (obtained from https://casa.nrao.edu ) using task "importasdm", then write it out as a UVFITS file using task "exportuvfits". Then have fun with TVPLT and all your favorite tasks! Help for these types of questions are available through the ALMA helpdesk..