how to remove a package which post-installation and pre-removal script fails?

I have an issue with the package openqrm.

How do I remove it?

root@wl183004:/# apt-get upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
1 not fully installed or removed.
After this operation, 0B of additional disk space will be used.
Do you want to continue [Y/n]? 
Setting up openqrm (4.6-ubuntu1) ...
.: 33: Can't open /usr/share/openqrm/etc/openqrm-server.conf
dpkg: error processing openqrm (--configure):
 subprocess installed post-installation script returned error exit status 2
Errors were encountered while processing:
 openqrm
E: Sub-process /usr/bin/dpkg returned an error code (1)

root@wl183004:/# apt-get -f install
Reading package lists... Done
Building dependency tree       
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
1 not fully installed or removed.
After this operation, 0B of additional disk space will be used.
Setting up openqrm (4.6-ubuntu1) ...
.: 33: Can't open /usr/share/openqrm/etc/openqrm-server.conf
dpkg: error processing openqrm (--configure):
 subprocess installed post-installation script returned error exit status 2
Errors were encountered while processing:
 openqrm
E: Sub-process /usr/bin/dpkg returned an error code (1)

root@wl183004:/# apt-get remove --purge openqrm
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libshadow-ruby1.8 bind9 libopenipmi0 nagios-plugins-basic open-iscsi
  nagios-plugins-standard memcached libupsclient1 collectd-core nagios-images
  bind9utils tftpd-hpa radiusclient1 libdbi0 libphp-adodb collectd libruby
  aoetools facter dhcp3-server open-iscsi-utils liboping0 libmemcached2
  libradius1 libyajl1 nagios-plugins puppet-common puppetmaster
  libopenssl-ruby1.8 libopenssl-ruby libesmtp5 libxmlrpc-ruby
Use 'apt-get autoremove' to remove them.
The following packages will be REMOVED:
  openqrm*
0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
1 not fully installed or removed.
After this operation, 78.2MB disk space will be freed.
Do you want to continue [Y/n]? 
(Reading database ... 313464 files and directories currently installed.)
Removing openqrm ...
.: 32: Can't open /usr/share/openqrm/etc/openqrm-server.conf
dpkg: error processing openqrm (--purge):
 subprocess installed pre-removal script returned error exit status 2
.: 33: Can't open /usr/share/openqrm/etc/openqrm-server.conf
dpkg: error while cleaning up:
 subprocess installed post-installation script returned error exit status 2
Errors were encountered while processing:
 openqrm
E: Sub-process /usr/bin/dpkg returned an error code (1)
root@wl183004:/# 

You might try to upgrade the package before purging it. In some cases, the new package will fix the removal script (dpkg is made so that new packages can fix even the transition scripts of old packages).

If that doesn't work, have a look at /var/lib/dpkg/info/openqrm.postinst like Kyle suggested, locate the line that fails, comment it out and try to purge again. Repeat until success.

The following worked for me:

• rm -rf /var/lib/dpkg/info/openqrm.*
• rm -rf /usr/share/openqrm
• rm -rf /etc/default/openqrm
• rm -rf /etc/init.d/openqrm
• apt-get purge openqrm

Just try to touch the missing file. If this is just one file missing file it could be a great workaround.

touch /usr/share/openqrm/etc/openqrm-server.conf

Now try to remove the package with apt-get or aptitude.

Look at /var/lib/dpkg/info/openqrm.postinst and see what it's trying to do