I am showing the last two commands. Update and upgrade are normal.
sudo apt-get remove nodejs npm
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package 'npm' is not installed, so not removed
The following packages will be REMOVED:
nodejs
0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
After this operation, 44.7 MB disk space will be freed.
Do you want to continue? [Y/n] y
[master b0fbdfe] saving uncommitted changes in /etc prior to apt run
Author: root <root@localhost>
(Reading database ... 55409 files and directories currently installed.)
Removing nodejs (6.12.0-1nodesource1) ...
Processing triggers for man-db (2.7.0.2-5) ...
[master 1981638] committing changes in /etc after apt run
Author: root <root@localhost>
2 files changed, 2 deletions(-)
delete mode 120000 alternatives/nodejs
delete mode 120000 alternatives/nodejs.1.gz
and while installing npm:
sudo apt-get install nodejs npm
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
nodejs : Conflicts: npm
E: Unable to correct problems, you have held broken packages.
and I still the npm version:
npm -v
2.15.11