Removing Vista

I have two hard drives ,each hard drive is partitioned into 2.

Drive 1

Partition C:
Partition D:

Drive 2

Partition E:

Partition F:

I have Vista Home Premium on C: Drive
Have Windows 7 on E: Drive

My Boot File is on the C : Drive for both Operating Systems.

If I want to remove Vista on Drive 1 , Partition C: First of all what would
be the easiest way of removing Vista? Reformat the drive or can you
uninstall it with the programs??

If I do Format the C: Drive,I would loose the Boot Manager File. I would
probably not be able to even boot into Win 7. If I can not boot into 7 Can I
insert the DVD do a repair to bring back the Boot file to C:?

Or can I just use a second party Boot Manager like Easy BCD to configure
Boot manager??
Thank You

Doug