Here are some different ways to access the unit:
Serial
Connection
Use the 9-pin serial to RJ45 cable provided to connect your PC to the 675's management port.

Use Hyperterminal (comes with Win9x) or the communication program of your choice to connect to the proper COM port.

38400, 8, N, 1
Telnet
Connection
Note:

The default for CBOS 2.0.1 and 2.1.0 is for telnet access to be enabled and to allow telnet access to anyone.

The default for CBOS 2.2 is to disallow telnet access until exec and enable passwords are set.

Enable telnet access.

enable

set telnet enable

- or -

set telnet remote 10.0.0.2 (to allow access from this IP only)

write

Make sure you don't leave telnet access enabled unless you have exec and enable passwords set!

If you are on the local machine, you can telnet to the local IP of 10.0.0.1 or you can access the router remotely by opening a telnet session to the Global IP.
HTTP (web)
Connection
Note:

The default for CBOS 2.0.1 and 2.1.0 is for web access to be enabled and to allow web access to anyone.

The default for CBOS 2.2 is to disallow web access until exec and enable passwords are set.

There is an open bug report (CSCdm11515) stating that changes made via the web interface will not be saved to nvram. This means that any changes will be lost if the 675 is rebooted. If you use the web interface to make changes you'll need to do a write using either a telnet or serial connection.

Enable web access.

enable

set web enable

- or -

set web remote 10.0.0.2 (to allow access from this IP only)

write

Make sure you don't leave web access enabled unless you have exec and enable passwords set!

Use a web browser to access the router via the Global IP.