The best view is through the browser by checking the url from the AWS console.
However, sometimes these it's not easy/possible, and then it's easier to do it by tunneling ssh into mplayer:
> ssh aws_cam@{cam_IP} cat /tmp/results.mjpeg | mplayer -demuxer lavf -lavfdopts format=mjpeg:probesize=32 -
Forum link: https://forums.aws.amazon.com/thread.jspa?messageID=861852
Deployed code is located at for the root:root (user:group) so accessing it requires sudo:
/opt/awscam/greengrass/ggc/deploymet/lambda/{lambda_arn}
It's Ok to just update the code there without deploying through the AWS console, however, changes are not deployed to the device automatically. Changes are refreshed on start of the GreenGrass service, i.e.
systemctl restart --no-block greengrassd.service