Does anyone know how to edit a Sims 1 skin in this way???

hey all-

does anyone know how to edit a Sim skin so that you can change its default formal wear, sleep wear, swim wear etc. to something else?

see- i have a few skins that look totally messed up if you put them in the pool or to bed cuz the default attire doesnt look right with the head.

i have the Grim Reaper, Frankenstein, and Servo Sim skins that look totally wrong in those other forms since the heads are so different. i don't even wanna redesign them for the other attire. i'd be happy with just making the attire the same for all activities. anyone know how to do that? :)

-MB7