The tricks for replacing eyes are:
pull the eyes apart, without touching the eyelashes or make-up
pop the eye out and remove all the packing
scrunch the packing tightly into the new eye
pull the eyes apart, without touching the eyelashes or make-up
pop the new eye back in
The tricks for reattaching loose eyelashes are:
apply a small amount of glue to a paperclip, pin or other tool
pull the eyelash gently back and apply glue to the back of the eyelash (not the doll)
holding the ends of the eyelash and not touching the glue, press it carefully into the position you want it to stick
hold for 5 seconds and let go