depends on the type of battery connection.
Normal post and clamp, you loosen the bolt that goes across the end of
the clamp, stck a big screwdriver in to lever it open and pull it off.
The other one you remove a screw from the middle of the connector and
pull the cable off.
Get a little battery post brush and clean it before reinstalling.
Make sure the cable cannot touch the other terminal.
If it is in good condition then removal is obvious and I would assume your
not being silly enough to ask. So obviously yours are a top post, encrusted
in crud, like most of them out there.
With these what I do is use a couple pair of vice grips to try to undo the
bolt, if the bolt snaps then no big deal. Then use a punch and hammer
aganst the inside side of the clamp where the bolt goes through, hit it a
few times that will help to loosen the clamp. If the clamp is still glued
to the post then use a clamp puller.
Once you have the clamp off, soak in water and baking soda, then wire
brush it to get all the corrosion off. Usually by working at the bolt with
vice grips you can get it out of the clamp then put a new bolt in, but if
the clamp is too badly deteriorated then just replace the entire cable.
On reeassembly make sure to use the anticorrosion spray.
Usually you do not need the pullers/spreaders. Usually a wrench of
appropriate size loosens the nut on the clamp. Then, hopefully you can
wiggle it loose by hand. If not, a large conventional screwdriver can
be stuck in the slot and twisted a little. This usually spreads the
clamp enough to wiggle it loose.