[ILUG] dual boot situation

[Tom]

my much abused home machine, in retaliation for years of abuse, finally 
attempted hari kiri some time back, in the form of massive hard disk corruption.
(I never paid much attention to those humidity acclimitisation warings in 
repairing PC books, but in retrospect maybe keeping it in a damp shed for a 
month and then bringing it indoors and switching it on was dumb)

No worries though, a second drive and more use of the `dd` command than I care
to recall got things almost back to the way they were.

However I would like now to get rid of the helplessly ruined old hard drive.
I need to free up some space in the machine - at the moment the only way I can 
use the floppy is to leave the side off of the box and plie up books beside it
and put the floppy on top of them. (I already ruined one floppy drive by trying
to use it vertical)

Because at first only some of the partitions were corrupt I used both
drives for months, transferring stuff to hdb when needed.
This means that now my debian and LFS installations on hdb now have fstab and
other such files refering to hdb, which I would like to make hda.

The questions are :

how feasable is it to take out the old drive and make hdb into hda
I know I need to change fstab and lilo.conf . What else may need 
reconfiguration?

the plan is to edit necessary files, remove the damaged drive, make current 
hdb master, boot with some rescue disk, run lilo.

Is this as mental as it seems to me or might it work. I'm prepared to risk the 
stuff on here because it is very much a test bed for mad notions anyway.

Tom