You want to be taken by the hand? OK
Method 1 : If you Google "Grub Manual" you will see the steps are fully documented in Chapter 3.1
Method 2 : A text book called “Linux in a Nutshell” by Siever, Figgins and Webber also describes the steps in detail in its Chapter 4.
Method 3 : Off my head the steps are
(a) You boot up a Live CD that has Grub inside, say Ubuntu, Puppy, Mepis, Linxu rescue CD, Mandriva...
(b) You give a command to Linux to demand it to report back to you where the hell has it hidden the Stage1 file you after by
find / -name stage1
(c) You then change directory into it, slip a floppy into the drive (no need to format) and type out the following command
dd if=stage1 of=/dev/fd0 bs=512 count=1
dd if=stage2 of=/dev/fd0 bs=512 seek=1
(d) You go to the bank and open a desposit box to lock up this floppy which is the most lethal weapon in booting. There is no PC system this floppy cannot boot.
If you want to try this weapon on your XP, which I don't have a clue where it is installed but say it is at the usual place of the first partition of your first hard disk then these lines on booting up a Grub floppy (in a Grub prompt) will fire its asx up
If your Red Hat is in the second partition and its Grub menu is working then it will answer this call in a Grub prompt
If you smash Red Hat's Grub to pieces and flush it down the toilet so that there is NO bootable available inside Red Hat the Grub floppy can still boot it. So look after the Grub floppy. Buy a shot gun to guard it if you have to.
I always try to persuade others to use a Live CD as the standard tools to rescue a Linux but in your case you have Red Hat. Red Hat installation CD has a "rescue" section on booting up. You can use it to "source" the necessary Grub files to make the Grub floppy. In fact Method 2 above was written using Red Hat distro. I just booted up my Red Hat 9 and found out stage1 is available in /usr/share/grub/i386-redhat subdirectory. Using Red Hat installation CD saves you the trouble of getting a Linux Live CD.