Overview: fdisk w/ a W95 partition table
mkdosfs

If you need the step by step, it’s below:

fdisk /dev/sd(whatever drive you want to reparition, ‘b’ in this case), then follow along:

The number of cylinders for this disk is set to 20023.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition’s system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)

Command (m for help): n

Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-20023, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-20023, default 20023):
Using default value 20023

Command (m for help): t
Selected partition 1
Hex code (type L to list codes): c
Changed system type of partition 1 to c (W95 FAT32 (LBA))

Command (m for help): p

Disk /dev/sdb: 164.6 GB, 164696555520 bytes
255 heads, 63 sectors/track, 20023 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x000f0136

Device Boot Start End Blocks Id System
/dev/sdb1 1 20023 160834716 c W95 FAT32 (LBA)

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: If you have created or modified any DOS 6.x
partitions, please see the fdisk manual page for additional
information.
Syncing disks.

root@sbrescue:/# mkdosfs /dev/sdb1
mkdosfs 3.0.1 (23 Nov 2008)
root@sbrescue:/# mount /dev/sdb1 /mnt
root@sbrescue:/# cd /mnt
root@sbrescue:/mnt# touch asdf
root@sbrescue:/mnt# ls
asdf
root@sbrescue:/mnt#

All done! =D