Damaged plants

[MYellowRose]

HELP!
Some of my sisters plants, that I have, have damaged parts on them. Most of these plants are just long leaves or fronds or whatever they are called. Some of the leaves are brown around the edges and other leaves seem totally dead. Should I cut off the damaged parts and pull out the dead leaves or cut them off at the bottom?
I don't want to do more damage to them but they need help and I don't want the plants to die completely.
I think they are sansaveria (may not be correct spelling) or something related. Some are green with yellow along the outside edges and others are just green.
I'm not sure what has caused the damage and I want, as I said, to make sure they don't die completely. These plants are in containers and I hope to repot many of them and was wondering if I should do all the work at the same time.

[daphodil]

If it's turning brown because of the wrong light conditions or humidity, etc. that can be corrected.
Here's what I could find in a couple houseplant books:
Sansevieria trifasciata:
. . . "Leaf sections of the snakeplant will root and grow if the base is inserted just below the surface of the rooting medium. . ." *from Decorating with Houseplants (69)
". . .bowstring hemp, devil's tongue, snake plant. . . it is native to both Africa and India. . . clusters of greenish white flowers appear only rarely. *Use standard indoor potting soil; give average house temperature and humidity." from House Plants A to Z (90)
I would probably remove the injured leaves, but be careful not to cut down so much that the plant cannot recover. . . I've killed my share of houseplants that way!
Or, it seems you could try finding a healthy cutting and try to save it that way. . .