Restoring GRUB of my Linux partition

I know, this is maybe sound silly. But I always install a linux distro GRUB on MBR. Since usually I had more than one linux distro on my disc, after the installation process I have to edit the /boot/GRUB/menu.lst file by handand added parameter so GRUB can boot into each distros
I stuck to a problem when installing Solaris 10. Solaris boot manager – not GRUB since my version was released somewhere in 2005- cannot boot into my linux partition. I tried to search a kind of file menu.lst in Solaris partition but could not find one.

Then from a blog of Sun’s employee I knew that the solution is to install linux GRUB to it’s partition. And hopefully Solaris bootloader do the rest.

I get the installation CD of Archlinux, and boot the computer from CD. Select the option of installing bootloader, but this time I chose on /dev/hda1 where Archlinux resides.

I then reboot the computer. I choose my linux distro when Solaris boot manager asking what OS I want to boot into. Archlinux GRUB appears instantly and since there is no other option, it boots to Archlinux. Success

Now I have two kind of OS in my computer: Linux & Solaris. I wish to install more but my disc only 20 GB, which is effectively restrict me from installing other OS