Do I need a serial cable to reset passwd?

[futurekey]

Hi, Folks

I have a pogoplug pro running for quite some time following the arch arm wiki. Today I need to make some changes and I realized that I totally forgot the root passwd which was randomly selected when I was doing the install. I tried to clear the 2nd field in /etc/shadow but was not successful. Somehow it does not work with ssh. Permission denied and the shadow file gets updated with huge line of characters. Can anybody point me to the right direction? Do I need to make a serial cable for this or if there is an easier way around this? Thanks!

Tim