br
you cant remove usercode wth desktop manager.
here steps
1.backup the device using Desktop Manager if necessary.
2.run JL_Cmder and select reset to factory(The device will do a security wipe of the device; (meaning wipe your data but leave the OS, DO NOT use the "Wipe" command in JL_Cmder) then reboot leaving the OS, 3rd party apps but no data AND, best of all, NO IT policy whatsoever)
When you're done, simply restore your backup and you're good to go with no policy or locked firewall
gsmdocter