FIRE's prism mode differs so fundamentally from the echelle format that we are releasing a separate pipeline to handle its data reduction. The prism routines draw on many of the same codes at their foundation but are wrapped differently.
A standard FIREHOSE installation contains both the echelle and longslit packages so you do not need to download them separately. This cookbook describes the basic steps involved in reducing data with the low dispersion pipeline. This software is in an earlier revision stage and is therefore not as feature-rich as the echelle counterpart. However it should be straightforward to reduce data with a modest amount of patience, and should be very well suited to reducing data "on-the-fly" at the telescope.