Installing 4.0.3

[PATELMS at duvm.ocs.drexel.edu]

 We have two SUN machines and the configuration is as follows

1) SUN 4/260C
   8 MB of RAM
   480 MB storage
   * File Server

2) SUN 4/110
   8 MB of Ram
   Diskless Client

All these days, we were running OS 3.5. Now we have bought 4.0.3 and I am
asked to upgrade and install the new OS on these machines. Before
venturing in to this work which I have not done earlier, I thought of
asking for some advise from gurus in this net land.  Is there anything I
am suppose to know apart from the installing instructions from SUN so that
the installing process is painless and smooth.

Thnks for any suggestions.