Upgrade from v5.7 to v5.8
 
Remount the disk read/write (remount w).
Make sure to rename or backup files that you have made
changes to (rc.local or similar) and is included in
this upgrade.

Copy the patch to /tmp and in the /tmp directory do:
  
tar Uzxpf /tmp/patch.57-58.tar.gz

Adjust config files, restart daemons and remount the disk
read-only (remount r).
  
- - - - - - - - - - - - - - - - - - - - - - - - - - -
Added or changed files (included in the tar file):
   
---x------    1 root     root         4380 11 dec 15.26 ./bin/arch*
---x--x--x    1 root     root       626028 15 dec 15.25 ./bin/bash*
---x------    1 root     root        13008 11 dec 15.25 ./bin/dmesg*
---x--x--x    1 root     root        17440 11 dec 15.23 ./bin/getopt*
---x--x--x    1 root     root        41956 11 dec 15.23 ./bin/hwclock*
---x------    1 root     root        21728 11 dec 15.22 ./bin/logger*
-r-x------    1 root     root          963 14 jan 14.22 ./contrib/scripts/subnet*
-r--------    1 root     root          324  6 feb  2001 ./etc/config.data/atm0.nic
-r--------    1 root     root          284  6 feb  2001 ./etc/config.data/dummy0.nic
-rw-------    1 root     root          479 14 jan 15.14 ./etc/config.data/.README
-r--------    1 root     root            3 31 mar  1999 ./etc/config.flags/atm0.nic
-r--------    1 root     root            3 31 mar  1999 ./etc/config.flags/dummy0.nic
-rw-------    1 root     root         1356 14 jan 15.18 ./etc/config.flags/.README
-rw-r--r--    1 root     root           49 11 dec 11.11 ./etc/ld.so.conf
-r-x------    1 root     root         1456 15 dec 11.53 ./etc/rc.d/rc.0*
-r-x------    1 root     root         3232 16 dec 14.28 ./etc/rc.d/rc.inet*
-r-x------    1 root     root          394 16 dec 14.36 ./etc/rc.d/rc.inet.routes*
-r-x------    1 root     root         5219 14 jan 14.27 ./etc/rc.d/rc.interfaces*
-r-x------    1 root     root           67 16 dec 14.37 ./etc/rc.d/rc.lo*
-r-x------    1 root     root         6894 16 dec 14.36 ./etc/rc.d/rc.M*
-r-x------    1 root     root         2595 16 dec 16.01 ./etc/rc.d/rc.S*
-rw-------    1 root     root         1685 16 dec 14.35 ./etc/rc.d/README
-rw-r--r--    1 root     root            5 11 dec 11.11 ./etc/.version
---x------    1 root     root        14336 15 dec 11.46 ./sbin/agetty*
-r-x------    1 root     root        18477 16 dec 14.25 ./sbin/configure*
---x------    1 root     root       563296 16 jan 13.58 ./sbin/dhcpd*
---x------    1 root     root       150580 16 jan 13.58 ./sbin/dhcrelay*
---x------    1 root     root        76556 11 dec 15.24 ./sbin/fdisk*
---x------    1 root     root        68508 15 dec 11.46 ./sbin/mount*
---x------    1 root     root         4388 11 dec 16.24 ./sbin/remount*
-r-x------    1 root     root         3578 16 dec 14.20 ./sbin/setrouter*
---x------    1 root     root        95656 16 jan 14.02 ./sbin/tc*
---x------    1 root     root        30816 15 dec 11.46 ./sbin/umount*

Stuff that has been removed or must be changed by hand:
 
Edit /etc/motd to change the version number.
Remove the old interface files nic.*