squirrels are not used to submersion, so this will be a little tricky. hopefully they are young enough that they won't struggle much. i suggest you get a wide mug or a small bowl with steep sides. fill it with water that is warm, not hot. basically, it'll be like a mini jacuzzi. if you have very basic antibacterial soap, you can put a small amount in the water, but not too much. from then on, it's just a basic rub and wash.
if you need to wash their heads, don't pour the water on them; wet a hand towel and try to wipe it clean. avoid their eyes and mouths.
could you give us more information on the squirrels? are their eyes open? do they have fur? how big are they? this will help us determine what else you should do, such as feeding, warmth, shelter, etc..
i'm gonna email this to you too, just in case it's faster.
keep us updated.