[superuser]

[ame=http://www.vimeo.com/1669496]Change 4th Gen iPod Hard Drive on Vimeo[/ame]

If you need parts you can get them at one of these sites:
iPod Parts / Installation - iPod 4th Gen - ifixipodsfast.com iPod Repair / Parts
4G iPOD PARTS: RapidRepair
iPodParts.com is the iPod Parts, iPod Battery and iPod Parts Repair Value Choice
iPod 4th Gen Parts - iFixit
4G iPod Parts

Here to help if you have questions!