How to Check the version of and Update opatch utility

Checking the opatch utility version:
$ cd $ORACLE_HOME/OPatch
$ opatch lsinventory

Invoking OPatch 10.2.0.4.3
Oracle Interim Patch Installer version 10.2.0.4.3
Copyright (c) 2007, Oracle Corporation.  All rights reserved.
Oracle Home       : /u01/app/oracle/product/10.2.0
Central Inventory : /u00/app/oracle/oraInventory
   from           : /var/opt/oracle/oraInst.loc
OPatch version    : 10.2.0.4.3
OUI version       : 10.2.0.4.0
OUI location      : /u01/app/oracle/product/10.2.0/oui
Log file location : /u01/app/oracle/product/10.2.0/cfgtoollogs/opatch/opatch2013-05-27_16-24-15PM.log
Lsinventory Output file location : /u01/app/oracle/product/10.2.0/cfgtoollogs/opatch/lsinv/lsinventory2013-05-27_16-24-15PM.txt
--------------------------------------------------------------------------------
Installed Top-level Products (2):
Oracle Database 10g                                                  10.2.0.1.0
Oracle Database 10g Release 2 Patch Set 3                            10.2.0.4.0
There are 2 products installed in this Oracle Home.
Interim patches (1) :
Patch  8350262      : applied on Thu Nov 22 14:55:53 GMT-04:00 2012
   Created on 14 Sep 2010, 04:59:44 hrs PST8PDT
   Bugs fixed:
     8350262
--------------------------------------------------------------------------------
OPatch succeeded.



How to update the opatch utility?
Go to :
https://updates.oracle.com/Orion/PatchDetails/handle_plat_lang_change?release=80102000&plat_lang=46P&patch_file=&file_id=&password_required=&password_required_readme=&merged_trans=&aru=13116067&patch_num=6880880&patch_num_id=979663&default_release=80102000&default_plat_lang=23P&default_compatible_with=&patch_password=&orderby=&direction=&no_header=0&sortcolpressed=&tab_number=

Description OPatch 10.2
Product Universal Installer
Select a Release : ORACLE 10.2.0.0.0
Platform or Language   : ORACLE SOLARIS  ON SPARC(64-BIT)
Last Updated 07-NOV-2010
Size 27M (28674793 bytes)
Entitlement Class   Software
Classification   General

Download the patch
Transfer the patch p6880880_102000_SOLARIS64.zip to remote server and unzip it

Backup the existing OPatch directory
$ mv OPatch/ opatch_backup

$ mv p6880880_102000_SOLARIS64.zip $ORACLE_HOME
$ unzip_sparc p6880880_102000_SOLARIS64.zip
bash-3.00$ cd OPatch/
bash-3.00$ opatch lsinventory
Invoking OPatch 10.2.0.5.1

Oracle Interim Patch Installer version 10.2.0.5.1
Copyright (c) 2010, Oracle Corporation.  All rights reserved.


Oracle Home       : /u01/app/oracle/product/10.2.0
Central Inventory : /u00/app/oracle/oraInventory
   from           : /var/opt/oracle/oraInst.loc
OPatch version    : 10.2.0.5.1
OUI version       : 10.2.0.4.0
OUI location      : /u01/app/oracle/product/10.2.0/oui
Log file location : /u01/app/oracle/product/10.2.0/cfgtoollogs/opatch/opatch2013-05-27_16-33-16PM.log
Patch history file: /u01/app/oracle/product/10.2.0/cfgtoollogs/opatch/opatch_history.txt
Lsinventory Output file location : /u01/app/oracle/product/10.2.0/cfgtoollogs/opatch/lsinv/lsinventory2013-05-27_16-33-16PM.txt
--------------------------------------------------------------------------------
Installed Top-level Products (2):
Oracle Database 10g                                                  10.2.0.1.0
Oracle Database 10g Release 2 Patch Set 3                            10.2.0.4.0
There are 2 products installed in this Oracle Home.
Interim patches (1) :
Patch  8350262      : applied on Thu Nov 22 14:55:53 GMT-04:00 2012
Unique Patch ID:  13011839
   Created on 14 Sep 2010, 04:59:44 hrs PST8PDT
   Bugs fixed:
     8350262
--------------------------------------------------------------------------------
OPatch succeeded.
bash-3.00$