This guide assumes you have already followed the Setup Dev Mode page found here on the Wiki. If you haven't, do so now. This guide can be skipped on ERA devkits by instead using xbrun or using an unattended script to start a system telnet session via WDP.
Locate net1 on your local Windows installation at C:\Windows\System32\net1.exe. Connect to SystemOS over sftp using the DevToolsUser creds explained above. If not already there, navigate to D:\DevelopmentFiles. Copy net1.exe from your local PC to the SystemOS at this path. This is required as though SystemOS includes net/net1, they are restricted to certain certificate capabilities. This restriction doesn't appear to apply to copied versions of the exe, hence the instructions above.
SSH into SystemOS using the DevToolsUser user. Navigate to D:\DevelopmentFiles if not already there and run the following command to create a new Windows User. Replacing "myexampleuser" with the username of your choice, and "supersecret" with the password of your choice respectively.
After your user has been created, go ahead and exit out of the DevToolsUser ssh session. Then in a command prompt, run following command, replacing "myexampleuser" and the IP address with your devkit's IP address respectively.
Enter your password, and if everything went well, you should be dropped to a command prompt in your user folder.