HELLO
I WANT TO KNOW HOW TO REMOVE OLD NET CARD DRIVER (integrated AMD PCnet family Ethernet card) and how to install a new 3com card and what is the changes in tcp/ip and ibmcom i shall made
my system is os/2 warp 3 on a Compaq deskpro 5133 [...]
Well, seeing that you have received no replies to your basic question, I want to welcome you to the OS/2 World! Below is the bare scheme of what is to be done:
At your OS/2 window command prompt, type:
MPTSclick yes, if needed, to the IBM informational dialog and you will be offered the
following dialog
If you will be installing a NIC driver, then select the button labeled
Install, and you will be subsequently presented with another
dialog prompting you to specify the path of the Nework Information Files (.NIF). Simply provide the path to where those are and select
OK; the utility will install your NIF --make sure to note down the name of the driver reported by the utility when it successfully completes.

If you will be configuring (i.e., removing and/or adding Network card NIFs and/or Nework protocols, select
Configure button, of course. You will be presented with
an additional dialog like this
Select
Configure once more and you will be presented with the next screen. Looking straight at the screen, on the upper left corner you have the available Network card NIFs; on the upper right corner will be the available protocols that you can install
after you have successfully installed a Network card NIF, of course.
Finally on the bottom window, you will see your current configuration for your Network card NIF and the associated protocols. Make a note of the existing protocols, specially if your current setup was working fine.
To remove an existing NIF and Protocol association (from the window below) that will effectively remove them from your OS/2 configuration files (after you reboot), you must first remove the protocol before attempting to remove the NIF; else
you will see the following error
To install another Network adapter NIF, you select it from the available ones
in your upper left window (a 3Com in this example) and select the button Add. You will see the NIF added to your bottom window. It wil be ready to accept a protocol from the upper right window:

Now, from the upper right window, select (one of) the protocol(s) that you want to associate with this NIF, say IBM TCP/IP implementation.
Once you select the Add button your selected protocol will appear under your highlighted NIF (3Com in this case).

Save your changes by selecting the
Ok button on the right and subsequently
Exit and agree to have your OS/2 CONFIG.SYS modified (you may decide to make a back up copy first by pressing CTRL-ESC and selecting to open another OS/2 command prompt
before the modification takes place).
After you are done with your task, you may want to write a short how-to article, blog, wikki, etc., and post it here (or somewhere else) to help others who will come across a similar issue

P.S. Moderator, you posted before I finished this.