You have to remove grub=pc and grub2-common. grub is a transitional package used to handle upgrades to GRUB2:
apt-cache show grub
Description: GRand Unified Bootloader (dummy package)
This is a dummy transitional package to handle upgrades.
Note: This package depends on `grub-pc', which upgrades your
system to GRUB 2. If you want to continue using GRUB Legacy, it
is provided in the `grub-legacy' package.
I suggested you use apt-get purge
instead of apt-get remove
because purge removes the packages plus their configuration files.
I tried it on my Wheezy installation in a VM and effed it up. After doing:
apt-get purge grub-pc and grub2-common
apt-get install grub-legacy
Checking the version of GRUB gave:
sudo grub-install --vgrub-install
But on rebooting, I still got my GRUB2 boot screen.
Checking the /boot/grub directory still showed grub.cfg and other GRUB2 related files. There was no stage1 or stage2 etc files. I purged the grub-legacy package and deleted all GRUB2 related files and re-installed the grub-legacy package:
sudo apt-get purge grub-legacy
sudo rm -r /boot/grub /etc/default/grub* /usr/share/grub
sudo apt-get install grub-legacy
But now there was no /boot/grub directory. So grub-install gave:
sudo grub-install /dev/sda
Stage1 file not read correctly.
I knew better but still decided to reboot since I saw grub-legacy files in /boot/grub. Now I'm at the grub rescue prompt. Ah well, serves me right. Now I need to get my Wheezy bootloader up but I have no idea what to do at the rescue prompt.
Will try though and let you know.
Edit: I think it's failing of my ext4 fs. As far as I can recall, grub-legacy did not support ext4 fs.