First you need following packages to install

gcc-3.4.6-sol10-sparc-local.gz
libiconv-1.13.1-sol10-sparc-local.gz
libintl-3.4.0-sol10-sparc-local.gz
sudo-1.7.2p5-sol10-sparc-local.gz

Install with following command

pkgadd -d downloadPath/filename

If you are unable to find sudo package online, your Solaris Sparc Companion disk contains it

Directory in Solaric Sparc Companion disk which contain sudo is “SFWsudo”

If I assume your path to package is /cdrom/Solaris_sparc/sparc/components/SFWsudo

Install by following command

pkgadd –d /cdrom/Solaris_sparc/sparc/components/  SFWsudo

After your installation is complete

First find the path of binary and configuration files, following is my example:

grep sudoers /var/sadm/install/contents

/opt/sfw/etc/sudoers f none 0440 root root 589 50133 1104945433 SFWsudo
/opt/sfw/man/man4/sudoers.4 f none 0444 root bin 57547 31697 1104945433 SFWsudo
/usr/local/share/vim/vim73/ftplugin/sudoers.vim f none 0644 bin bin 426 36373 1285497623 SMCvim
/usr/local/share/vim/vim73/syntax/sudoers.vim f none 0644 bin bin 19276 64681 1285497623 SMCvim 

Now my I can see that my configuration file i.e. sudoers is in /opt/sfw/etc/sudoers and for sudo it is always in the same path but in /bin directory i.e. /opt/sfw/bin/sudo

Steps for sudo to work properly:

1. Add /opt/sfw/bin  in your PATH if it is not available – check with echo $PATH
2. Sudoers file default permission will be read only, for making changes you will need to first change the permission of sudoers file and edit your changes and revert back the permission of sudoers file to (chmod 440)
3. Sudo binary which is in /opt/sfw/bin should have the sticky bit set permission i.e. (chmod u+s )

And you are done here, enjoy and start using sudo