How to kill zombie process in Solaris 9?

Dear Team,

One zombie process has been found in our V890 server. 

root@vomssz1> ps -ef | grep [d]efunct

    root  4340  4144  0                   0:00 <defunct>

root@vomssz1> ptree 4144

4144  /export/home/oracle/crs/10.1.0/bin/crsd.bin

  4340  <defunct>

root@vomssz1> uname -a

SunOS vomssz1 5.9 Generic_118558-38 sun4u sparc SUNW,Sun-Fire-V890

How to kill this zombie process? I've seen a solution in the document ID 1007095.1.

" Under solaris 9 or later. preap command may be used to reap zombie process".

1. How to use preap command to kill zombie process? 

2. What are the things to be considered while executing preap command?

3. Will it impact the performance of the system?