Short solution...
___________________________________________________________
___________________________________________________________

$(lsof | grep $(ls -1 .nfs*) | awk '{print "kill -9 " $2}')
___________________________________________________________
___________________________________________________________

".nfs000000..." files appear, when an open file on the NFS share gets removed. Such files get deleted automatically when they're closed.

On the NFS share there's a script named "testscript.ksh" and an old vim backup copy of it:
==========================================================================================
goofy:ORCL:/app/orcl/nfs/bin$ ll
total 168
drwxr-xr-x 6 oracle orainst  4096 Jun 10 10:16 .
drwxrwxrwx 4 oracle orainst  4096 Jun 10 10:17 ..
-rw-r--r-- 1 oracle orainst 16384 Jun  9 17:39 .testscript.ksh.swp
-rwxr-xr-x 1 oracle orainst 14510 Jun 10 10:16 testscript.ksh


Deleting the vim backup copy...
===============================
goofy:ORCL:/app/orcl/nfs/bin$ rm .testscript.ksh.swp


...results in an ".nfs000000..." file
=====================================
goofy:ORCL:/app/orcl/nfs/bin$ ll
total 168
drwxr-xr-x 6 oracle orainst  4096 Jun 10 10:17 .
drwxrwxrwx 4 oracle orainst  4096 Jun 10 10:17 ..
-rw-r--r-- 1 oracle orainst 16384 Jun  9 17:39 .nfs00000000041a3cb50000000b
-rwxr-xr-x 1 oracle orainst 14510 Jun 10 10:16 testscript.ksh


Trying to delete the ".nfs000000..." file fails:
================================================
goofy:ORCL:/app/orcl/nfs/bin$ rm .nfs00000000041a3cb50000000b
rm: cannot remove `.nfs00000000041a3cb50000000b': Device or resource busy


Use "lsof" command ("list open files") to identify the process who holds the open file:
=======================================================================================
goofy:ORCL:/app/orcl/nfs/bin$ lsof | grep nfs00000000041a3cb50000000b
vi         6618     oracle    4u      REG               0,19    16384  68828341 /app/orcl/nfs/bin/.nfs00000000041a3cb50000000b (10.182.138.201:/vol/data/stoerm_a_nor_2)


Verify the identified process using "ps -ef"...
===============================================
goofy:ORCL:/app/orcl/nfs/bin$ ps -ef | grep 6618
oracle    6618   670  0 Jun09 pts/0    00:00:00 vi testscript.ksh
oracle   20691 16405  0 10:21 pts/6    00:00:00 grep 6618


...and kill it!
===============
goofy:ORCL:/app/orcl/nfs/bin$ kill -9 6618


Now the ".nfs000000..." file has disappeared:
============================================= 
goofy:ORCL:/app/orcl/nfs/bin$ ll
total 152
drwxr-xr-x 6 oracle orainst  4096 Jun 10 10:21 .
drwxrwxrwx 4 oracle orainst  4096 Jun 10 10:17 ..
-rwxr-xr-x 1 oracle orainst 14510 Jun 10 10:16 testscript.ksh