how to enforce password change from Powershell?

At first I was thinking about how to set pwdLastSet to some old value? It is possible by:
$userObj = get-ADUser -Properties pwdLastSet
$userObj.pwdLastSet = 0
set-ADUser -instance $userObj
$userObj.pwdLastSet = -1
set-ADUser -instance $userObj

but it can set two possible values - never (0) and now (-1) - other values are invalid. When I tried to do it by:
$dt = Get-Date
$dt = $dt.AddDays(-70)
$userObj.pwdLastSet = $dt.ToFileTimeUTC()
set-ADUser -instance $userObj

Every time it was finished with error - the same is from Active Directory Users and Computers and from ADSIEdit. It is possible only from SYSTEM level.

For me - the only possible way how to do it is by preparation special kind of granullar password policy and connecting it with selected users.

shared process lanmanserver stuck?

Windows 2008 Server and lanmanserver stuck. No errors, no warnings - just only stucked process. Process kill by:
taskkill /f /pid [pid]
is not working because I can't specify subprocess - I can kill all the subprocesses. I decided to config lanmanserver with its own process by:
sc config lanmanserver type= own
after restart it is much better - process is not stucked and it is working.