The negative wire and battery connector to my Mazda 626 need replacing. Is this something a layman could do?
The car is a Mazda 626 LX, 1991 aka "the deathtrap" . Walmart just replaced the battery, but said that they do not have the parts to replace the negative wire and the connector that leads to the battery. just, what they showed me was that the connector to the negative port of the battery was all corroded and crumbly, and the wire coming out of the connector was old, crakced and frayed. Both, they said, should be replaced, though the car and battery now work.
I guess usually what I am asking is, if you do not know lots about cars, is this something that may be done, or is this asking for catastrophe and am I supposed to just pay a mechanic to do it?
Thanks.

