Develop a simple routine for the bath. Try not to feel rushed. Don't try to do this if you're tired. Bathing can be fatiguing for both of you, so don't try to do this on a day you have something else planned. Reset water heater temperature to 110 degrees to prevent burns.
Bathing can be a shower, a tub bath or a sponge bath.
The shower may be easiest and require only a little assistance from you. Some spouses find it helpful to get right in the shower and shower together. Hand held shower heads may cause less fear of flowing water. Don't assume the person is really showering. You need to look in.