How to add folders to the PATH environment variable?

I'm trying to install the ndless SDK using Cygwin. I've managed to complete all the instructions up to "Now add the following folders to your PATH environment variable." I've tried running the command (with the path to ndless substituted in) in the cygwin terminal, but I get a rather long error message.
All I've come up with is that it might be caused by a wrong carriage return character, but I'm new to bash and unix, so I don't have any idea how to fix this. I've tried running d2u .bashrc and d2u bash_profile, but I got a "command not found" error.
Can someone explain what I'm doing wrong and how to fix it?
All I've come up with is that it might be caused by a wrong carriage return character, but I'm new to bash and unix, so I don't have any idea how to fix this. I've tried running d2u .bashrc and d2u bash_profile, but I got a "command not found" error.
Can someone explain what I'm doing wrong and how to fix it?