I don't know what the ASI fridge is, but here's how the Westy fridge comes
out.  I just did it.

There are two screws on each side.  On the right, just open the cabinet
door.  On the left, open the low door for one, and the high "hatch" for the
other.

Remove the vent on the left outside of the cab.

Turn off the outside gas valve.

Reach inside the under the sink cabinet and detach the gas connection, as
well as two electrical connections, the DC and the AC.

The fridge (Westy) should now be loose, but mine was stuck tight...adhered
after 20 years of sitting there.  After getting more and more confident that
there wasn't anything substantial holding it in, I just pulled really firmly
and it came out finally.

That's it.

Paul